1 CE 8601/ DESIGN OF STEEL STRUCTURAL ELEMENTS UNIT I INTRODUCTION AND ALLOWABLE STRESS DESIGN Structural steel types – Mechanical Properties of structural steel- Indian structural steel products-Steps involved in the Deign Process -Steel Structural systems and their Elements- -Type of Loads on Structures and Load combinations- Code of practices, Loading standards and Specifications - Concept of Allowable Stress Method, and Limit State Design Methods for Steel structures-Relative advantages and Limitations-Strengths and Serviceability Limit states. Allowable stresses as per IS 800 section 11 -Concepts of Allowable stress design for bending and Shear –Check for Elastic deflection-Calculation of moment carrying capacity –Design of Laterally supported Solid Hot Rolled section beams-Allowable stress deign of Angle Tension and Compression Members and estimation of axial load carrying capacity. PART-A (2 marks) 1. What are the types of steel available? o wrought iron – Carbon content: not greater than 0.15% o Steel - Carbon content: 0.15% to 1.5% o Cast iron - Carbon content :2% to 4% Based on carbon content o Mild steel – 0.15 to 0.25% o Medium carbon steel - 0.25 to 0.6% ( rail wheels) o High carbon steel - 0.6 to 1.5% 2. What are the structural steel sections available? o Angle sections o Channel sections o I-sections o T-sections o Flat sections o Steel plates o Corrugated sheets o Round bars o Square bars 3. What is meant by structural system?
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CE 8601/ DESIGN OF STEEL STRUCTURAL ELEMENTS
UNIT I INTRODUCTION AND ALLOWABLE STRESS DESIGN
Structural steel types – Mechanical Properties of structural steel- Indian structural steel
products-Steps involved in the Deign Process -Steel Structural systems and their
Elements- -Type of Loads on Structures and Load combinations- Code of practices,
Loading standards and Specifications - Concept of Allowable Stress Method, and Limit
State Design Methods for Steel structures-Relative advantages and Limitations-Strengths
and Serviceability Limit states.
Allowable stresses as per IS 800 section 11 -Concepts of Allowable stress design for
bending and Shear –Check for Elastic deflection-Calculation of moment carrying capacity
–Design of Laterally supported Solid Hot Rolled section beams-Allowable stress deign of
Angle Tension and Compression Members and estimation of axial load carrying capacity.
PART-A (2 marks)
1. What are the types of steel available?
o wrought iron – Carbon content: not greater than 0.15%
o Steel - Carbon content: 0.15% to 1.5%
o Cast iron - Carbon content :2% to 4%
Based on carbon content
o Mild steel – 0.15 to 0.25%
o Medium carbon steel - 0.25 to 0.6% ( rail wheels)
o High carbon steel - 0.6 to 1.5%
2. What are the structural steel sections available?
o Angle sections
o Channel sections
o I-sections
o T-sections
o Flat sections
o Steel plates
o Corrugated sheets
o Round bars
o Square bars
3. What is meant by structural system?
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Bridges, buildings, dams, transportation facilities, liquid or gas storage
facilities, industrial factories and plants, power generation and transmission units
4. What are the basic structural elements?
o Axially Loaded Members in Tension
o Columns – Axially Loaded Members in Compression
o Beams – Shear and Bending Moment
o Planar Trusses – All Members Axially Loaded
o Planar Trusses – All Members Axially Loaded
o Arches – Direct Compression
o Cables – Flexible Members in Tension
o Rigid Frames
o Plates or Slabs
o Thin Shells
5. What are the properties of structural steel?
o Density. Density of a material is defined as mass per unit volume.
o Elastic Modulus.
o Poisson's Ratio.
o Tensile Strength.
o Yield Strength.
o Melting Point.
o Specific Heat.
o Hardness.
6. Which type of steel is most commonly used in general construction? Why?
Mild Steel is most commonly used in general construction because of its
durability and malleability
7. Define permissible stresses and Working stresses.
Permissible stresses
Permissible stresses = factor of safety / yield stress
Working stresses:
The stresses used in practical design are working stresses and they
should never exceed the permissible stresses specified by codes.
8. How the rolled steel beams are classified?
Indian Standard junior beams (ISLB)
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Indian Standard light beams (ISLB)
Indian Standard medium weight beams (ISMB)
Indian Standard wide flange beams (ISWB)
9. What are the load combinations for the design purposes?
Dead load + Imposed Load (Live load)
Dead Load + Imposed Load + Wind Load or earthquake load
Dead Load + Wind Load or Earthquake load
10. Mention the advantages and disadvantages of steel structures?
Advantages:
Ability to resist high loads
Due to its high density, steel is completely non-porous
Durability
Easy to disassembling or replacing some steel members of a structure
Disadvantages:
Corrosion
At high temperature steel loses most of its strength, leading to deformation
or failure
11. What is meant by tensile stress?
When a structural member is subjected to direct axial tensile load, the stress
is known as tensile stress (σst). The tensile stress is calculated on net cross-
sectional area of the member.
σst=Pt/An
Where, Pt is the direct axial tensile load and An is the net cross-sectional area of the
member.
12. What is meant by compressive stress?
When a structural member is subjected to direct axial compressive load, the
stress is known as compressive stress (σsc). The compressive stress is calculated on
gross cross-sectional area of the member.
σsc = Pc/Ag
Where, Pc is the direct axial compressive load and Ag is the gross-sectional area of
the member.
13. Define bearing stress.
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When a load is exerted or transferred by the application of load through one
surface for another surface in contact, the stress is known as bearing stress ( σ p).
the bearing stress is calculated on net projected area of contact.
σp = (P/A)
Where, P = load placed on the bearing surface
14. What is working stress?
The working stress is also termed as allowable stress or permissible stress.
The working stress is evaluated by dividing yield stress by factor of safety. For the
purpose of computing safe load carrying of a structural member, its strength is
expressed in terms of working stress. The actual stresses resulting in a structural
member from design loads should not exceed working stress.
15. Define factor of safety.
The factor of safety is defined as the factor by which the yield stress of the
material is divided to give the working stress (permission stress) in the material.
16. What are the methods employed for the design of the steel framework?
Simple design
Semi-rigid design
Fully rigid design
Plastic design.
17. What are the assumptions made in simple design?
o The beams are simply supported
o All connections of beams, girders, or truss are virtually flexible and are
proportioned for the reaction shears applied at the appropriate eccentricity
o The members in compression are subjected to forces applied at the
appropriate eccentricities.
o The members in tension are subjected to longitudinal forces applied over
the net area of the sections
18. Define Modulus of Elasticity
The modulus of elasticity is defined as the ratio of longitudinal stress to the
longitudinal strain within the elastic region; it is denoted by ‗E‘.
19. Define Poisson‟s Ratio.
The Poisson‘s ratio is defined as the ratio of transverse strain to the
longitudinal strain under an axial load. It is denoted by ‗μ‘ or 1/m. the value of
Poisson‘s ratio for steel within the elastic region ranges from 0.25 to 0.33.
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20. What are the steps involved in structural design?
o Forces or loads
o Structural arrangement and material selection
o Analyzing internal stresses
o Proportioning of members
21. What is meant by Allowable Stress Design?
Allowable Stress Design (ASD) is also referred to as the service load
design or working stress design (WSD). The basic conception (or design
philosophy) of this method is that the maximum stress in a structural member is
always smaller than a certain allowable stress in bridge working or service
conditions. The allowable stress of a material determined according to its nominal
strength over the safety factor.
22. What are the advantages and disadvantages of allowable stress design?
Advantages:
Elastic analysis for loads becomes compatible for design.
Old famous books are according to this method.
Experienced engineers are used to this method.
In past it was the only method for design purposes.
This method is included in AISC-05 specifications as an alternate method.
Disadvantages:
Same factor of safety is used for different loads.
Latest research and literature is very limited.
Failure mode is not directly predicted.
With some overloading, the material stresses increase but do not go to
collapse.
The failure mode cannot be observed.
The warning before failure cannot be studied precisely.
Results cannot be compared with experimental tests up to collapse.
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24. What is meant by limit state design? (IS800:2007-Pg: 28)
Limit state design method is technologically sound method which results in
significant economy in design of structures. The design of a structure to satisfy all
appropriate requirements derived from probability considerations is referred to as a
limit state design.
25. State the different limit states. (IS800:2007-Pg: 28)
The limit states are broadly grouped in to two major types, namely:
o Limit state of strength
o Limit state of serviceability.
26. What are the four types of serviceability limit states applicable to steel
structures? (IS800:2007-Pg: 28)
Deflection
Durability
Vibration
Fire resistance
27. Define durability. (IS800:2007-Pg: 2)
It is defined as ability of the structure to maintain its level of reliability and
performing the desired function in the working environment under exposure
conditions, without deterioration of cross sectional area and loss of strength due to
corrosion during its life span.
28. How the loads are classified? (IS800:2007-Pg: 4)
Dead load
Live load
Earthquake load
Wind load
Dynamic loads.
29. What is a partial safety factor? (IS800:2007-Pg: 4).
The safety of the structure depends on each of the two principal design
factors namely, load and material strength, which are not the functions of each
other. Each of the two factors contributes partially to safety and they are termed as
partial safety factors.
30. Define design load.
The partial safety factor for loads is a load factor which is multiplied to
characteristic load, gives the design load.
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Design load = γf x Characteristic load
UNIT II CONNECTIONS IN STEEL STRUCTURES
Type of Fasteners- Bolts Pins and welds- Types of simple bolted and welded connections
Relative advantages and Limitations-Modes of failure-the concept of Shear lag-efficiency
of joints- Axially loaded bolted connections for Plates and Angle Members using bearing
type bolts –Prying forces and Hanger connection– Design of Slip critical connections with
High strength Friction Grip bolts.-Design of joints for combined shear and Tension-
Eccentrically Loaded Bolted Bracket Connections- Welds-symbols and specifications-
Effective area of welds-Fillet and but Welded connections-Axially Loaded connections for
Plate and angle truss members and Eccentrically Loaded bracket connections.
Types of sections – Net area – Net effective sections for angles and Tee in tension – Design of
connections in tension members – Use of lug angles – Design of tension splice – Concept of
shear lag
PART-A (2 marks)
1. What are the various types of connections used for connecting the structural
members?
o Riveted connections
o Bolted connections
o Pin connections
o Welded connections
2. Define riveting.
Riveting is a method of joining two or more structural steel components by
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inserting ductile metal pins, called rivet.
3. Define nominal diameter of rivet.
It is the diameter of the unheated rivet measured before driving. It is the stated
diameter of the rivet, available in the market
4. Define gross diameter of rivet.
It is the diameter of the rivet in the hole, measured after driving. It is taken
equal to the diameter of the rivet hole.
5. What is meant by pitch of rivet?
The pitch of the rivets is the distance between centers of two adjacent rivets in a
row.
6. Define gauge line.
It is the line of rivets, which is parallel to the direction of stress
7. What is meant by gauge distance and edge distance?
Gauge distance is the perpendicular distance between two adjacent gauge
lines. This is also called as back pitch. Edge distance is the distance of the edge of
the member or the cover plates from the center of extreme rivet hole.
8. Define staggered pitch.
It is also called as alternate pitch or reeled pitch. The staggered pitch is defined
as the distance measured along one rivet line from the center of a rivet to the center
of the adjoining rivet on the adjacent parallel rivet line.
9. Define lap.
It is the distance normal to the joint between edges of the overlapping
plates in a lap joint or between the joint and the end of cover plates in a butt joint.
19. What are the types of riveted joints?
Lap joint
(a) Single riveted lap joint
(b) Double riveted lap joint
Butt joint
(a) Single cover butt joint
(b) Double cover butt joint
20. Define Lap joint and Butt Joint.
Lap joint:
When one member is placed above the other and these two are connected
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by means of rivets, then the joint is known is lap joint.
Butt Joint:
When the plates are placed end-to-end and flushed with each other and are
joined by means of cover plates, the joint is known as Butt joint.
21. What are the types of failures occur in riveted joint?
Shear failure of rivets
Shear failure of plates
Tearing failure of rivets
Bearing failure of plates
Splitting failure of plates at the edges
Bearing failure of rivets.
22. Write about Minimum pitch and Maximum pitch
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Minimum pitch:
The distance between centers of adjacent rivets should not be less than 2.5
times the gross diameter of the rivet
Maximum pitch:
The maximum pitch should not exceed 12t or 200 mm whichever is less in
case of compression member, and 16t or 300 mm whichever is less in case of
tension member.
The distance between centers of any two consecutive rivets in a line adjacent and
parallel to an edge of an outside plate shall not exceed (100mm + 4t) or 200 mm,
whichever is less in compression or tension members.
If the line of rivets (including tacking rivets) does lie in the direction of stress, the
maximum pitch should not exceed 32 t or 300 mm whichever is less, where t is the
thickness of the thinner outside plate
23. What is edge distance?
A minimum edge distance of approximately 1.5 times the gross diameter of
the rivet measured from the centre of the rivet hole is provided in the rivet joint.
24. What is meant by limit state design? (IS800:2007-Pg: 28)
Limit state design method is technologically sound method which results in
significant economy in design of structures. The design of a structure to satisfy all
appropriate requirements derived from probability considerations is referred to as a
limit state design.
25. State the different limit states. (IS800:2007-Pg: 28)
The limit states are broadly grouped in to two major types, namely:
o Limit state of strength
o Limit state of serviceability.
26. What are the four types of serviceability limit states applicable to steel
structures? (IS800:2007-Pg: 28)
Deflection
Durability
Vibration
Fire resistance
27. Define durability. (IS800:2007-Pg: 2)
It is defined as ability of the structure to maintain its level of reliability and
performing the desired function in the working environment under exposure
conditions, without deterioration of cross sectional area and loss of strength due to
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corrosion during its life span.
28. How the loads are classified? (IS800:2007-Pg: 4)
Dead load
Live load
Earthquake load
Wind load
Dynamic loads.
29. What is a partial safety factor? (IS800:2007-Pg: 4).
The safety of the structure depends on each of the two principal design
factors namely, load and material strength, which are not the functions of each
other. Each of the two factors contributes partially to safety and they are termed as
partial safety factors.
30. Define design load.
The partial safety factor for loads is a load factor which is multiplied to
characteristic load, gives the design load.
Design load = γf x Characteristic load
31. Define bolt.
A bolt is a metal pin with a head formed at one end and the shank threaded
at the other end in order to receive a nut.
32. What are the advantages of bolted connections? (May / June 2007)
There is silence in preparing bolted connection. In riveting, hammering is
done. The hammering causes noise in the riveting.
There is no risk of fire in bolted connection. The rivets are made red hot in
riveting and there is risk of fire.
The bolted connections may be done quickly in comparison to the riveting.
Though the cost of bolts is more than the cost of rivets, the bolted
connections are economical to use because less persons are required for
installation, and the work proceeds quickly.
Noiseless
Easy to dismantle and reuse the materials.
33. What are the various types of bolts used for structural purposes? (May /
June 2007)
Unfinished bolts
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Turned bolts
Black bolts
High strength bolts
34. What are the advantages of HSFG bolts?
Do not allow slip between the connected members.
Loads are transferred by friction only.
Due to high strength less number of bolts are required.
No noise pollution
Deformation is minimized.
35. Define nominal diameter and gross diameter of bolt.
Nominal diameter of bolt:
The nominal diameter of a bolt is the diameter of unthreaded shank of bolt.
Gross diameter of bolt:
The gross diameter of a bolt is the nominal diameter of the bolt.
36. Define slip factor.
The slip factor is defined as ratio of the load per effective interface,
required to produce slip in a pure shear joint to the total shank tension induced in
the bolts.
37. Define weld.
The welding is one of the methods of connecting the structural members. In
the welding, a metallic link is made between the structural members. The weld is
defined as a union between two pieces of metal at faces rendered plastic or liquid
by heat or by pressure or both.
38. Write about the advantages of welding.
There is silence in the process of welding.
There is safety of welding operator in the welding
The welding may be done quickly in comparison to the riveting.
The welded joints have better appearance than riveted joints.
The welded joints are more rigid than the riveted joints
39. List the various types of welded joints.
Butt weld
Fillet weld
Slot weld and plug weld
Spot weld
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Seam weld
Pipe weld
40. Write about the disadvantages of welding.
The members are likely to distort in the process of welding.
A welded joint fails earlier than riveted joint, if the structure is under
fatigue stresses.
There is a greater possibility of brittle fracture in welding than the rivet.
The inspection of welded joint is more difficult and more expensive than
the riveted joint.
More skilled person is required in the welding than in the riveting
41. What is the effective area of butt weld?
The effective area of a butt weld is taken as the product of the effective
throat thickness and the effective length of butt weld.
42. How the length of bolt is calculated?
The length of bolt is equal to the distance from the underside of the bolt
head to the extreme end of the shank, including any camber or radius.
43. What is meant by stiffened & unstiffened seat connection?
The simple seat connection consists of an angle with its horizontal leg at its
top, to receive the reaction from the beam and transfer it to the column or beam.
The seat connection requires more space in the vertical direction.
When the beam reaction is large (>100 KN) the angle alone cannot support
it. In such case the horizontal leg of an angle is stiffened (strengthened) by means
of one or two tight fitting angles. Such connection is called as stiffened seat
connection.
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44. What are the types of welding process?
Electric arc welding
Gas welding
Termite welding
Forged welding
Resistance welding.
45. How to calculate the efficiency of a joint?
The efficiency of the joint is the ratio of actual strength of connection to the
gross strength of connected member, expressed in % as,
Least actual strength of the joint
Efficiency of joint = X 100
Gross strength of solid plate member
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UNIT-3 COMPRESSION MEMBERS
Types of compression members – Theory of columns – Basis of current codal provision
for compression member design – Slenderness ratio – Design of single section and
compound section compression members – Design of laced and battened type columns –
Design of column bases – Gusseted base
PART – A (2 marks)
1. What is meant by strut? (IS800:2007-Pg: 5)
A strut is defined as a structural member subjected to compression in a
direction parallel to its longitudinal axis. The term strut is commonly used for
compression members in roof trusses.
2. What is meant by effective sectional area?
The effective sectional area of a compression member is the gross cross
sectional area of the member. The deduction is not made for members connected
by rivets, bolts and pins.
3. Define slenderness ratio of compression member.
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The slenderness ratio of a compression member is the ratio of effective
length of compression member (l) to appropriate radius of gyration (r).
4. Draw the diagram of buckling of column.
5. What are the assumptions made in Euler‟s analysis?
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The material is homogeneous and linearly elastic (i.e. it obeys Hooke‘s
Law).
The strut is perfectly straight and there are no imperfections.
The loading is applied at the centroid of the cross section at the ends.
6. Define buckling load. (IS800:2007-Pg: 1)
The buckling load is defined as the load at which a member or a structure
as a whole collapses in service (or buckles in a load test). The buckling is defined
as the sudden bending, warping, curling or crumpling of the elements or members
under compressive stresses.
7. What are the buckled modes for different end conditions?
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8. What is meant by built-up compression members?
The built-up compression members are needed when the single rolled steel
sections are not sufficient to furnish the required cross-sectional area. A built-up
compression member may consist of two or more rolled structural steel sections
connected together effectively and acts as one compression member.
9. Define position restraint.
In position restraint end of the column is not free to change its position but
rotation about the end of eth column can take place e.g., hinged end of column.
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10. What are the different effective lengths for different boundary condition?
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11. Define effective length.
The effective length of a compression member is the distance between the
points of contra flexures of a buckled column. It depends on the actual length and
the end conditions in regards to restraint against rotation and transverse
displacement.
12. What is meant by actual length?
The actual length is taken as the length from centre-centre of intersections
with the supporting members.
` 13. How the effective length of column is determined?
The effective length of columns in framed structures may be obtained by
multiplying the actual length of the column between the centers of laterally
supporting members (beams) given with the effective length factor K.
Effective length = KL
14. Define single lacing & double lacing. (IS800:2007-Pg: 48 & 49)
Double laced system, on opposite faces of the components being laced
together shall preferably be in mutual opposed in direction.
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15. What are the forces acting on lacing system?
The forces acting on lacing system are transverse shear force and axial
force.
16. Draw the column base plate diagram. (Nov / Dec 2005)
17. Where should the splice plate be located in a column?(IS800:2007-Pg:46)
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18. What is the purpose for providing anchors bolt in base plate?
Anchor bolts are provided to stabilize the column during erection and to
prevent uplift for cases involving large moments. Anchor bolts can be cast-in place
bolts or drilled-in bolts. The latter are placed after the concrete in set and are not
too often used. Their design is governed by the manufacturer's specifications. Cast-
in-place bolts are hooked bars, bolts, or threaded rods with nuts placed before the
concrete is set.
19. What are the types of bases provided for connecting the column to the
base?
Slab base
Gusseted base
Moment resisting bass
20. Which column formula is recommended in IS 800:2007? (Pg: 34)
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21. Under what circumstances gusset base is used?
When the load on the column is large or when the column is subjected to
moment along with axial load, gusseted base is provided. It consists of a base plate,
gusset plate, connecting angles provided on either side of the column and web cleat
angle.
22. Write about batten plates in compression member.
When compression members are required for large structures like bridges, it
will be necessary to use built-up sections. They are particularly useful when loads
are heavy and members are long (e.g. top chords of Bridge Trusses). The cross
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section consists of two channel sections connected on their open sides with some
type of lacing or latticing (dotted lines) to hold the parts together and ensure that
they act together as one unit. The ends of these members are connected with
―batten plates‖ which tie the ends together.
23. What are the three classifications for determination of size of plate?
Class I- will pertain to all base plates the moment on which is so small in
proportion to the direct load that there is compression over the entire area between
the bottom of the base and its foundation
Class II- will pertain to comparatively small range of base plates which
have tension over a small portion - one - third or loss of the area
Class III- will include those which are exposed to a comparatively large
moment and which therefore have tension over a large portion - more than one -
third of the area between the bottom of the base plate and its concrete footing.
24. What are the functions of providing column bases?
The basic function of bases is to distribute the concentrated load from the
column over a larger area. The column load is distributed over the base plate and
then to supporting concrete and finally to the soil.
25. What is meant by column splice?
A joint in the length of a column provided, when necessary, is known as
column splice. It is also described as column joint.
26. List the limiting slenderness ratio of compression member carrying dead
load & live load. (April / May 2008)(IS800:2007-Pg: 20)
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27. What is meant by slab base?
The slab base as shown in Figure consists of cleat angles and base plate.
The column end is faced for bearing over the whole area. The gussets (gusset
plates and gusset angles) are not provided with the column with the slab bases. The
sufficient fastenings are used to retain the parts securely in plate and to resist all
moments and forces, other than the direct compression. The forces and moments
arising during transit, unloading and erection are also considered
UNIT4- BEAMS
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Design of laterally supported and unsupported beams – Built up beams – Beams subjected to
uniaxial and biaxial bending – Design of plate girders - Intermediate and bearing stiffeners –
Flange and web splices.
PART-A (2 marks)
1. What is meant by limit state design?
Designs should ensure that the structure does not become unfit for the use for
which it is required. The state at which the unfitness occurs is called a limit state.
2. What are special features of limit state design method?
o It is possible to take into account a number of limit states depending upon the
Particular instance
o This method is more general in comparison to the working stress method. In
This method, different safety factors can be applied to different limit states,
which is more rational than applying one common factor (load factor) as in the
plastic design method.
o This concept of design is appropriate for the design of structures since any new
knowledge of the structural behavior, loading and materials can be readily
incorporated.
3. Explain the behavior of steel beams?
Laterally stable steel beams can fail only by (a) Flexure (b) Shear or (c)
Bearing, Assuming the local buckling of slender components does not occur. These
three conditions are the criteria for limit state design of steel beams. Steel beams would
also become unserviceable due to excessive deflection and this is classified as a limit
state of serviceability. The factored design moment, M at any section, in a beam due to
external actions shall satisfy M < Md
Where Md= design bending strength
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4. Write Short notes on compact sections
When the lateral support to the compression flange is adequate, the lateral
buckling of the beam is prevented and the section flexural strength of the beam can be
developed. The strength of I-sections depends upon the width to thickness ratio of the
compression flange. When the width to thickness ratio is sufficiently small, the beam
can be fully plastified and reach the plastic moment, such section are classified as
compact sections.
5. What is meant by slenderness sections?
When the width to thickness ratio of the compression flange is sufficiently
large, local buckling of compression flange may occur even before extreme fiber yields.
Such sections are referred to as slender sections.
6. List the various factors affecting the lateral-torsional buckling strength.
Distance between lateral supports to the compression flange.
Restraints at the ends and at intermediate support locations (boundary
Conditions).
Type and position of the loads.
Moment gradient along the length.
Type of cross-section.
7. What are the classifications in Stiffeners?
a) Intermediate transverse web stiffeners
b) Load carrying stiffeners
c) Bearing stiffeners
d) Torsion stiffeners
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e) Diagonal stiffeners and
f) Tension stiffeners
8. Draw the curvature for flexural member performance and the classification of
cross sections.
9. How do you improve the shear resistance in plate girder?
Increasing in buckling resistance due to reduced c/d ratio;
The web develops tension field action and this resists considerably larger
Stress than the elastic critical strength of web in shear
10. Write about the Box girders
The design and detailing of box girders shall be such as to give full advantage of
its higher load carrying capacity. Diaphragm shall be used where external vertical as
well as transverse forces are to be transmitted from one member to another. The
diaphragms and their fastenings shall be proportioned to distribute other force applied
to them and in addition, to resist the design transverse force and the resulting shear
forces. The design transverse force shall be taken as shared equally between the
diaphragms
11. Write Short notes on Purlin.
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Purlins attached to the compression flange of a main member would
normally be acceptable as providing full torsional restraint; where purlins are
attached to tension flange, they should be capable of providing positional restraint
to that flange but are unlikely (due to the rather light purlin/rafter connections
normally employed) to be capable of preventing twist and bending moment based
on the lateral instability of the compression flange.
12. Write the Special features of limit state design method?
Serviceability and the ultimate limit state design of steel structural systems and their
components.
o Due importance has been provided to all probable and possible design conditions
that could cause failure or make the structure unfit for its intended
o The basis for design is entirely dependent on actual behavior of materials in
structures and the performance of real structures, established by tests and long-
term observations
o The main intention is to adopt probability theory and related statistical methods
in the design.
o It is possible to take into account a number of limit states depending upon the
particular instance
13. What is meant by laterally supported beam?
The laterally supported beams are also called laterally restrained beams. When
lateral deflection of the compression flange of a beam is prevented by providing
effective lateral support, (restraint) the beam is said to be laterally supported. The
effective lateral restraint is the restraint which produces sufficient resistance in a plane
perpendicular to the plane of bending to restrian the compression flange of a beam from
lateral buckling to either side at the point of application of the restraint.
31
14. Write a note on built up beams.
The built-up beams are also termed as compound beams or compound girders.
The built-up beams are used when the span, load and corresponding bending moment
are of such magnitudes that rolled steel beam section become inadequate to provide
required section modulus. The built-up beams are also used when rolled steel beams are
inadequate for limited depth.
15. What are the elements of plate girder?
32
The vertical plate of the plate girder is termed as web plate. The angles
connected at the top and bottom of the web plate are known as flange angles. The
horizontal plates connected with the flange angles are known as flange. Plates or cover
plates. The web plate, flange angles and flange plates are shown in Fig. The bearing
stiffeners, intermediate stiffeners and horizontal stiffeners used with the plate girder are
shown in Fig.
33
16. Under what circumstances web plates are stiffened and unstiffened?
A web plate is kept unstiffened when the ratio of clear depth to thickness of web
is less than 85. It does not require stiffeners. A web plate is called stiffened, when the
ratio of clear depth to thickness of web is greater than 85 and stiffeners are provided to
contribute additional strength to web.
17. What is meant by plastic method of design?
Steel being a ductile material it can absorb large deformations beyond elastic
fracture. Steel processes reserved strength beyond yield strength. The method using this
reserved strength is called plastic method of design.
18. Define shape factor.
The ratio of plastic moment to elastic moment Mp / My is the property of cross
sectional area and is not dependent on material properties. This ratio is called as shape
factor.
19. What is meant by plastic hinge?
Plastic hinge is the yield section of the beam, which acts as if it were hinged,
except with a constant restraining plastic moment.
20. Define yield length.
The yield length is the length of the beam over which the moment is greater than
or equal to the yield moment. It depends upon the type of loading and the cross section
of the structural member.
21. What are the methods of plastic analysis?
Static method
Kinematic method or mechanism method.
22. What is meant by static and Kinematic method?
Static method: The lower bound theorem states a load computed, on the basis of
assumed equilibrium moment diagram, in which moments are not greater than plastic
moment Mp, is less than or at the best equal to the true collapse load. i.e., W ≤ Wc
(collapse load)
Kinematic method: The upper bound theorem states a load computed, on the
basis of assumed mechanism, will always be greater than or at the best equal to the true
collapse load. i.e., W ≥ Wc
23. What are the guide lines to locate the plastic hinges?
The plastic hinges occur,
At the points of maximum moment
34
At the connections involving change in geometry.
Under the concentrated load
At the points of zero shear in a span, loaded by udl.
24. Define virtual work.
It states that ‗work done by the load during small motion of collapse
mechanism must be equal to the work absorbed in the plastic hinges‘.
25. what is meant by complete collapse, partial collapse and over complete
collapse?
Complete collapse: The number of plastic hinges, H required to form
complete collapse = R+ 1, where R is the degree of redundancy of the
structure. H = R + 1
Partial collapse: The number of plastic hinges, H required to form partial
collapse is < R+ 1. (i.e., H < R + 1)
Over complete collapse: The number of plastic hinges, H required to form
over complete collapse is > R+ 1. (i.e., H > R + 1)
26. What is meant by lateral buckling of beam?
A long beam with laterally unrestrained compression flange when incrementally
loaded, first deflects downwards and when load exceeds a particular value; it tilts
sideways due to instability of compression flange, and rotates about longitudinal axis.
This phenomenon is known as laterally buckling or torsional buckling of beam
27. How the laterally supported beam fails?
The laterally supported beam can fail by,
Flexure
Shear
Bearing.
28. What is web buckling and web crippling?
A heavy concentrated load produces a region of high compressive stresses in the
web either at support or under the load. This causes the web either to buckle or to
cripple.
Web buckling occurs when the intensity of compressive stress near the centre of
the section exceeds the critical buckling stress of web acting as a strut. This type of
failure is more in the case of built up sections having greater ratio of depth to thickness
of the web.
29. What is the purpose of providing stiffener in plate girder?
35
In the plate girder the depth of the web is kept large for economy and hence it is
made thin to reduce the self weight of the girder. A very thin web may buckle laterally
or may cripple under the heavy concentrated load. In such a case the web is strengthened
by providing stiffeners.
30. Under what circumstances load bearing stiffeners are used in plate girder?
The load carrying stiffeners are attached with the web plate of the plate girder to
avoid local bending failure of flanges, crushing of web and buckling of web plate. They
are provided under the heavy concentrated loads and the reactions at supports.
31. Under what circumstances bearing stiffeners are used in plate girder?
Bearing stiffeners should be provided for webs where forces are applied through
the flange by loads or reactions exceeding the local capacity of the web at its connection
to the flange.
32. What is the purpose of providing intermediate stiffeners?
The intermediate transverse stiffeners are provided to strength the buckling
strength of web. They remain effective after the buckling of web and provide anchorage
for tension field.
33. What is the main function of providing horizontal stiffener in plate girder?
The main function of horizontal stiffener is to increase the buckling resistance of
the thin web. They are located in the compression zone. It prevents the web from
bending laterally.
34. What are the reasons behind splicing in plate girder?
The joint in the plate girder called splicing becomes necessary for plate girders of
longer span due to the following reasons:
o The rolled steel plates are manufactured up to a limited length. When the
maximum manufactured length is insufficient for full length, splicing becomes
necessary.
o For convenience of handling during transportation and erection it is essential that
the plate is too long.
o Due to unsymmetrical loading the thickness of plate may change.
35. What are the types of splices?
36
Flange splice
Web splice.
36. How the flange area of a plate girder is designed?
Flange area, Af = M / (D fyf / Ymo)
M = factored moment
D = total depth of girder
fyf = Yield stress of steel
Ymo = Partial safety factor of material.
UNIT5- ROOF TRUSSES AND INDUSTRIAL STRUCTURES
Roof trusses – Roof and side coverings – Design of purlin and elements of truss; end bearing
– Design of gantry girder
PART-A (2 marks)
1. What are the types of load that may act on roof trusses?
o Dead load
Load from coverings, purlins, self weight of trusses and bracing.
o Live load
o Wind load
2. How economical spacing of roof trusses obtained?
The economical spacing of trusses is between 1/3 to 1/5 of span.
3. List the various forces acting on a gantry girder.
o Weight of the trolley or crab
o Weight of the crane girder
o Impact loads – it is due to sudden application of brakes.
o Lateral load (surge load) – transverse to the rail
o Longitudinal load (drag load)
37
4. What are the loads to be considered while designing the purlins?
o Dead load
Weight of roof sheets
Self weight of purlin
o Live load
o Wind load acting on roof area.
5. List the various types of roof sheetings commonly used.
o Asbestos cement sheets
o Tiles
o Galvanized corrugated iron sheets
o Aluminium sheets
o Slate roofing.
6. Which section is best suited for a purlin?
o Angle section
o Channel section
o I-section
7. How is the selection of section made for roof truss element?
o The members of the truss are made of either rolled steel sections or built-up
sections depending upon the span length and intensity of loading.
o Rolled steel single or double angles, T-section, hollow circular, square or
rectangular sections are used in the roof trusses of industrial buildings.
o In long span roof trusses and short span bridges, heavier rolled steel
sections, such as channels and I – sections are used.
o Built-up I-sections, channels, angles and plates are used in the case of long
span bridge trusses.
8. How to fix the spacing of trusses?
The economical spacing of trusses is between 1/3 to 1/5 of span.
o For lighter load, carrying no snow or superimposed load except wind, the
larger spacing may be more economical.
o Spacing of 3- 4.5 m for spans up to 15m and 4.5 – 6 m for spans of 15 – 30
m may be economical.
o The spacing of long span trusses may be 12 – 15 m.
9. What are economical considerations for industrial truss?
38
o Method of fabrication and erection to be followed, facility for shop
fabrication available, transportation restrictions, field assembly facilities.
o Preferred practices and past experience.
o Availability of materials and sections to be used in fabrication.
o Erection technique to be followed and erection stresses.
o Method of connection preferred by the contractor and client (bolting,
welding or riveting).
o Choice of as rolled or fabricated sections.
o Simple design with maximum repetition and minimum inventory of
material.
10. Write about basics of plastic analysis?
In plastic analysis and design of a structure, the ultimate load of the
structure as a whole is regarded as the design criterion. The term plastic has
occurred due to the fact that the ultimate load is found from the strength of steel in
the plastic range.
This method is rapid and provides a rational approach for the analysis of
the structure. It also provides striking economy as regards the weight of steel since
the sections required by this method are smaller in size than those required by the
method of elastic analysis.
11. What is meant by first yield moment?
As W is increased gradually, the bending moment at every section increases
and the stresses also increase. At a section close to the support where the bending
moment is maximum, the stresses in the extreme fibers reach the yield stress. The
moment corresponding to this state is called the first yield moment My, of the cross
section.
12. Write about Principles of plastic analysis.
(i) Mechanism condition: The ultimate or collapse load is reached when a
mechanism is formed. The number of plastic hinges developed should be just
sufficient to form a mechanism.
(ii) Equilibrium condition: ΣFx = 0, ΣFy = 0, ΣMxy = 0
(iii) Plastic moment condition: The bending moment at any section of the structure
should not be more than the fully plastic moment of the section.
13. Explain about Crane gantry girders.
39
The function of the crane girders is to support the rails on which the
traveling cranes move. These are subjected to vertical loads from crane, horizontal
lateral loads due to surge of the crane, that is, the effect of acceleration and braking
of the loaded crab and swinging of the suspended load in the transverse direction,
and longitudinal force due to acceleration and braking of the crane as a whole.
14. What are assumptions are made for arrangement of live load in the
analysis of frames?
a) Consideration is limited to combination of:
i) Design dead load on all spans with full design live load on two adjacent
spans and
ii) Design dead load on all spans with full design live load on alternate
pans.
b) When design live load does not exceed three-fourths of the design dead load,
the load
arrangement of design dead load and design live load on all the spans can be
used.
15. Explain about Drift Analysis
Drift in building frames is a result of flexural and shear mode contributions,
due to the column axial deformations and to the diagonal and girder
deformations, respectively. In low-rise braced structures, the shear mode
displacements are the most significant and, will largely determine the lateral
stiffness of the structure.
In medium to high-rise structures, the higher axial forces and deformations
in the columns, and the accumulation of their effects over a greater height, cause
the flexural component of displacement to become dominant.
16. Calculate the permissible deflection for a truss of 10 m span.
(IS800:2007-Pg: 31 – table 6)
Deflection limit = span / 150
= 10 x 1000 / 150
= 66.67 mm
17. Sketch the various types of roof truss.
40
41
CE 8601/ DESIGN OF STEEL STRUCTURAL ELEMENTS
UNIT-1
INTRODUCTION AND ALLOWABLE STRESS DESIGN
PART-B:
1. A tie member in a roof truss consists of two ISA 90 mm x 60 mm x 8 mm.
Determine the safe load to carrying capacity of the member if
(i) The angles are on the same side of the gusset plate
(ii) The angles are on either side of the gusset plate. 16mm rivets are used for connection
at the ends and the members tracked along the length. (Use Working Stress Design)
2. Design a tension member to carry axial tension of 450 kN. Use 10mm thick gusset
plate and 20mm diameter black bolts.Use Allowable Stress Method.
3. Design a built up column with two channel sections. The column is of 6.4m effective
length and supports a load of 1000kN. Use WSD.
4. Design a compression member to carry a load of 500 kN. Use WSD.
5. Estimate the axial load carrying capacity of a column ISA 90 90 8.
6. Calculate the axial load carrying capacity of a column ISMC 400.
7. Design a simply supported(laterally supported) of effective span of 12m to carry o
factored load of 70 kN/m the depth of the beam is restricted to 500mm. Use Allowable
stress design.
8. Calculate the moment carrying capacity of the beam ISMB 550 @1.037 kN/ m.
9. Design a compression member using angle section to carry 300 kN load. Use WSD.
UNIT-II
CONNECTIONS IN STEEL STRUCTURES 1. (i) Design a double bolted lap joint for a plate of 20mm thickness to carry its full load.
(ii) A double riveted lap joint in plates 10mm thick is made with 16mm rivets at 60mm
pitch. Estimate hoe the joint will fail and calculate its efficiency if the tearing strength
42
of the plates is 475 N/mm2 and shearing and bearing strength of the rivets are 380
N/mm2 and 750 N/mm2 respectively.
2. An ISLC 300@331 N/m is used to transmit a force of 500kN.The channel section is
connected to a gusset plate of 8mm thick. Design a fillet weld if the overlap is limited to
350mm.
3. Determine the safe load and the efficiency of a double cover butt joint. The main plates
are 12mm thick connected by18mm diameter rivets at a pitch of 100mm.design the cover
plates also. What is the percentage reduction in the efficiency of the point if the plates are
lap jointed.
4. Design a single bolted double cover butt joint to connect plates of fy 410 grade having
thickness 16mm.Use M16 bolts of grade 4.6.Fine the efficiency of the joint.
5. A tie member of a roof truss consists of 2 ISA 90mmx60mmx10mm. The angles are
connected on either sides of 12mm gusset plate and the member is subjected to the pull of
400kN.design the welded connections.
6. A single riveted double cover butt joint is used to connect two plates 12mm thick. The
rivets used are power driven 18 mm in diameter at a pitch of 60mm. Find the safe load per
pitch length and the efficiency of the joint.
7. A tie member consisting of angle section 80mm x60mm x8mm is welded to a 8mm
gusset plate. Design the weld to transmit a load equal to the full strength of the member.
8. A plate in which the axial tension is 520kN is to be provided with a splice joint. The
size of the plate is 400 mm x 20 mm. Design a suitable riveted joint.
9. Design a double riveted double cover butt joint connects two plates of 12 mm thick.
Adopt power driven rivets. Take fy = 250Mpa. Find also the efficiency of the joint.
10. A bracket is welded to a stanchion by fillet welds having a throat thickness of 9mm
and a load of 180 kN is applied in the plane of the bracket, as shown in the figure. The
weld extends round three sides and has the given dimensions. Determine the maximum
stress in the throat of the weld.
43
11. What are the types of load to be account for steel design?
12. A bracket carrying a load of 100 kN is connected to column by means of two
horizontal fillet welds, of 130 mm effective length and 10 mm thick. The load acts at 70
mm from the face of the column as shown. Find the throat stress. (May / June 2007)
13. A tie member 75 mm X 8mm is to transmit a load of 90 kN Design the fillet weld and
calculate the necessary overlap. (Nov / Dec 2007)
14. A single bolted double cover butt joint is used to connect two plates 8mmthick.
Assuming 20mm bolts at 50mm pitch calculate the efficiency of the joint. The thickness of
cover plate is 4mm
15. The figure shows the joint in the bottom chord continuous member of the truss. Design
the connection using M16 black bolt of property class 4.6 and grade Fe410 steel. Assume
edge distance of 35 mm and minimum pitch.
44
16. Design the seat angle connection between the beam ISMB 250 andcolumn ISHB 250
for a reaction from beam equal to 85 KN. Use M16 blackbolt of property class 4.6 and
grade Fe410 steel with fy =250 MPa.
17. A beam ISWB 550 having equal flange width to that of column, transfers a factored
end reaction of 275 KN to the flange of the column ISSC 250. Design the stiffened seat
angle connection using 20 mm bolts of grade 4.6, fy =250MPa.
UNIT III
TENSION MEMBERS
1. A tie member in a roof truss consists of two ISA 90 mm x 60 mm x 8 mm.
Determine the safe load to carrying capacity of the member if
(i) The angles are on the same side of the gusset plate
(ii) The angles are on either side of the gusset plate. 16mm rivets are used for connection
at the ends and the members tracked along the length.
2. A tension member is subjected to a pill of 300kN. Design suitable section if
(i) It consists of a single angle connected by one leg.
(ii) It consists of double angle on either side of gusset plate ant tacked along the
length.
3. Design a tension member to carry a load of 300kN. The two angles placed back to back
with
long leg outstanding are desirable. The length of the member is 2.9m.
4. Design a tension splice for tension member sections 160 mm x10 mm and 250 mm x12
mm.
The member is subjected to a pull of 200 kN.
5. Design a tension member to carry factored axial tension of 450kN. Use 10mm thick
gusset
plate and 20mm diameter black bolts.
6. (i) What is a Lug angle? Where it is used?
(ii) Design a splice to connect a 300mmx 20mm plate with 300mm x10mm plate to
carry
design load of 500kN.Use 20mm black bolts.
7. Design a tension member of length 3.6m between c/c of intersections and carrying a
pull of
150kN.The member is subjected to reversal of stresses.
8. Design a tension member to carry a load of 300kN. Two angles placed back to back
with long
45
leg outstanding are desirable. The length of the member is 3m.
9. A double angle ISA 75mm x75mm x 8mm back to back welded to one side of a 12mm
gusset
have allowable stress 150Mpa. Determine the allowable tensile load on the member and
weld
length and overlap length of gusset plate.
10. An ISA 100x100x12 is used as a tie riveted to a gusset plate with 24mm rivets
arranged in
one row along the length of the angle. Determine the allowable tension on the angle if
the
allowable tensile stress is 150Mpa.
UNIT-IV
COMPRESSION MEMBERS
1. Design completely a built up column composed of channel sections placed back to back
carrying an axial load of 1500 kN. Its length is 6m and it is effectively held in position at
both ends restrained against rotation at one end. Take fy = 250N/mm2
2. Design a gusseted base for a column ISHB [email protected]/m carrying an axial load of
2000kN. Take allowable bearing pressure in concrete as 4 N/mm2.
3. Design a built up column with two channel sections. The column is of 6.4m effective
length and supports a load of 1000kN.
4. Design a suitable slab base for a column section ISHB 300.subjecte4d to a load of
450kN. The base plate is to rest on a concrete pedestal of M20 grade.
5. Design a column with double lacing system to carry a factored axial load of
1800kN.The effective height of column is 4.5m. Use two channels placed back to back.
6. Design a gusseted base to carry a factored axial load 2500kN. The column consists of
ISHB 450 @ 0.855 kN/m with two cover plates 250mm x 20mm on either side. Take the
effective height of column as 4m.
7. Design a column with single lacing system to carry a factored axial load of 1500kN.
The effective height of the column is 4.2m.Use two channels placed toe to toe.
8. Design suitable slab base for a column section ISHB 400 @ 822 N/m, supporting an
axial load 500kN. The base plate is rest on a concrete pedestal of M20 grade concrete.
46
9. Design a laced column for an axial load of 1200 kN with an effective span of 7.5m has
one end fixed and the other end hinged. Use channels for main members and an angle for
lacing bars.
10. A column of ISHB 400 is subjected to an axial force of 750kN. Design suitable base
plate. Assume necessary data‘s required.
UNIT-V
DESIGN OF FLEXURAL MEMBERS
1. Design a built up beam section for a span of 8m to carry a uniformly distributed load of
15 kN/m and a central concentrated load of 100kN.The beam is laterally supported
throughout. Show the curtailment if plated also.
2. A plate girder of span 15m is made up of web plates of 1600mmx 8mm, flange angles
150mmx115mmx10mm and two flange plates 480mmx10mm it carries a uniformly
distributed load of 100 kN/m including its own weight. Design and Sketch the web splices
at 5m from one end.
3. Design a simply supported(laterally supported) of effective span of 12m to carry o
factored load of 70 kN/m the depth of the beam is restricted to 500mm.
4. Design a riveted plate girder using Fe 415 steel for a span of 22 m to carry a load of
25kN/m.
5. Design a simply supported beam of effective span 10m to carry factored load of
60kN/m, the depth of the beam is restricted to 500mm . Assume the beam is laterally
unsupported.
6. Design a welded plated girder using Fe 415 steel for a span of 25 m to carry a load of
30kN/m.
7. Design a simply supported beam to carry uniformly distributed load of 44 kN/m .The
effective
Span of beam is 8 m. The effective length of compression flange of the beam is also 8 m.
The ends of beam are not to free to rotate at the bearings.
8. The effective length of compression flange of simply supported beam MB 500 @0.869
kN/m.
Determine the safe uniformly distributed load per meter length which can be placed over
the beam having an effective span of 8 m. The ends of beam are restrained against rotation
at the bearings. ISMB 550 @1.037 kN/ m has been used as simply supported over a span
of 4 m. The ends of beam are restrained against torsion but not against lateral bending.
Determine the safe UDL per meter, which the beam can carry.
47
9. Design rolled steel I- sections for a simply supported beam with a clear span of 6m .it
carries a
UDL of 50 KN per metre exclusive of self-weight of the girder .the beam is laterally
unsupported.
10. Check the beam section WB 500 @1.45 kN/m against web crippling and web buckling
if reaction at the end of beam is 179.6 KN, The length of bearing plate at the support is
120 mm. Design bearing plate. The bearing plate is set in masonry.
11. A beam simply supported over an effective span of 7m, carries a uniformly distributed
load of 50kN/m inclusive of its own weight. The depth of the beam is restricted to 450mm.
design the beam, assuming that the compression flange of the beam is laterally supported
by a floor construction. Take fy = 250N/mm2 and E =2X105N/mm2. Assuming width of
the support is 230mm. (May/June 2007).
12. Design a bearing stiffener for a welded plate girder with the following specifications.
Web = 1000mm X 6mm thick. Flanges = 2 Nos. of 350X20mm plate on each side.
Support reaction = 350kN.Width of the support = 300mm.. (May/June 2007).
13 A simply supported steel joist with a 4.0m effective span carries a udl of 40kN/mover
its span inclusive of self weight. The beam is laterally unsupported. Design a suitable
section. Take fy = 250N/mm2. (Nov/Dec 2007)
14. Design the step by step procedure for design of vertical and horizontal stiffeners in a
plate girder. (Nov/Dec 2007)
15.Design a built up beam section for a span of 8m to carry a uniformly distributed load of
15 kN/m and a central concentrated load of 100 kn. The beams is laterally supported
through out. Show the curtailment of plates also.
16. A plate girder of span 15m is made-up of web plates of 1600mm x 8mm flange angles
150mmx 115mm x 10mm and two flange plates 480mm x 10mm it carries a uniformly
distributed load of 100kn/m including its own weight. Design and sketch the web splices
at 5m from one end.
17. Design a simply supported (laterally supported) of effective span 12m to carry a
factored load of 70kN/m. The depth of the beam is restricted to 500mm.
18. In an industrial building, the trusses of 16 m span and 4m rise are spaced at 8m apart
.The building is in medium wind zone in an industrial area of plain land. Design purlin.
19. Design a channel section purlin for the following data
Spacing of trusses = 4.2m
Spacing of purlins = 2 m
Live load on GC sheets = 0.6kN/m2
48
Wind load = 1.4kN/m2
Slope of main rafter = 31o
20. List out various elements of the roof truss and mark all its significance
CE 8602 - STRUCTURALANALYSIS-II
PART-A (Two Marks)
UNIT I
INFLUENCE LINES FOR DETERMINATE BEAMS
1. Define Influence line (or) Influence Line Diagram (ILD).
An influence line is a graph showing, for any given frame or truss, the variation of any
force or displacement quantity (such as shear force, bending moment, tension, deflection)
for all positions of a moving unit load as it crosses the structure from one end to the other.
2. What are the uses of influence line diagrams?
(i) Influence lines are very useful in the quick determination of reactions, shear force,
bending moment or similar functions at a given section under any given system of
moving loads.
(ii) Influence lines are useful in determining the load position to cause maximum value
of a given function in a structure on which load positions can vary.
3. Where do you get rolling loads in practice?
Shifting of load positions is common enough in buildings. But they are more
pronounced in bridges and in gantry girders over which vehicles keep rolling.
4. Name the type of rolling loads for which the absolute maximum bending moment
occurs at the midspan of a beam.
(i) Single concentrated load (ii) udl longer than the span (iii) udl shorter than the span
(iv) Also when the resultant of several concentrated loads crossing a span, coincides
with a concentrated load then also the maximum bending moment occurs at the centre
of the span.
49
5. What is meant by absolute maximum bending moment in a beam?
When a given load system moves from one end to the other end of a girder, depending
upon the position of the load, there will be a maximum bending moment for every section.
The maximum of these bending moments will usually occur near or at the midspan. The
maximum of maximum bending moments is called the absolute maximum bending
moment.
6. Where do you have the absolute maximum bending moment in a simply supported
beam when a series of wheel loads cross it?
When a series of wheel loads crosses a simply supported beam, the absolute maximum
bending moment will occur near midspan under the load Wcr , nearest to midspan (or the
heaviest load). If Wcr is placed to one side of midspan C, the resultant of the load system R
shall be on the other side of C; and Wcr and R shall be equidistant from C. Now the
absolute maximum bending moment will occur under Wcr . If Wcr and R coincide, the
absolute maximum bending moment will occur at midspan.
7. What is the absolute maximum bending moment due to a moving udl longer than
the span of a simply supported beam?
When a simply supported beam is subjected to a moving udl longer than the
span, the absolute maximum bending moment occurs when the whole span is loaded.
Mmax = wl 2/ 8
8. State the location of maximum shear force in a simple beam with any kind of
loading.
In a simple beam with any kind of load, the maximum positive shear force
occurs at the left hand support and maximum negative shear force occurs at right hand
support.
9. What is meant by maximum shear force diagram?
Due to a given system of rolling loads the maximum shear force for every
section of the girder can be worked out by placing the loads in appropriate positions.
50
When these are plotted for all the sections of the girder, the diagram that we obtain is
the maximum shear force diagram. This diagram yields the ‗design shear‘ for each
cross section.
10. Draw the influence line diagram for shear force at a point X in a simply supported
beam AB of span „l‟ m.
11. Draw the ILD for bending moment at any section X of a simply supported beam
and mark the ordinates.
12. What do you understand by the term reversal of stresses?
In certain long trusses the web members can develop either tension or compression
depending upon the position of live loads. This tendency to change the nature of stresses is
called reversal of stresses.
13. Define static indeterminacy of a structure.
51
If the conditions of statics i.e., ΣH=0, ΣV=0 and ΣM=0 alone are not
sufficient to find either external reactions or internal forces in a structure, the
structure is called a statically indeterminate structure.
14. Differentiate the statically determinate structures and statically indeterminate
structures.
Sl.No statically determinate
structures statically indeterminate structures
1
Bending moment and shear
force is dependent on member
properties.
Bending moment and shear force is
independent of member properties.
2 No stresses are caused due
to temperature change.
Stresses are caused due to temperature
change.
3 Conditions of equilibrium are
sufficient.
Conditions of equilibrium are
insufficient.
15. Write the condition of absolute maximum bending moment due to UDL is shorter
than the span.
If the length of udl is shorter than the span then absolute bending moment occurs at the
centre of the span when the udl is symmentrically placed in the span.
Absolute maximum BM = wl1/8* (2l- l1)
L=Span length
l1= UDL length
16. What is meant by train of concentrated loads?
A set of concentrated loads moving over a simply supported beam from left to right. It is
required to find out
Maximum Shear force
Maximum Bending moment
Absolute maximum shear in the beam
Absolute maximum bending moment in the beam.
17. What is meant by pin jointed plane frames?
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Pin-jointed determinate trusses are frequently employed as bridge girders. A trussed
bridge usually consists of two trusses cross wise connected by cross girders. For large spans
trussed bridges are used.
18. What is the use of cross girders in bridges?
Cross girders are interconnected by longitudinal stringer parallel to the traffic direction.
A wheel load is transmitted from deck slab to stringers. The cross girders will transfer the load
coming on them to the joints of truss. In general girders are used in small spans. In stressed
bridges there are two types
1. Through type
2. Deck type.
19. Define moving loads or rolling loads.
It is the load that changes in time the place to which is applied. Rolling loads are those
loads which roll over the given structural element from one end to the other end.
Examples: Trains on the track and Vehicle that pass the bridges.
20. Write the formula for shear force and bending moment in ILD calculation.
Maximum negative SF = x/l
Maximum positive SF = l - x/l
Maximum BM = x (l – x)/l
21. Define Trussed Beam.
A beam strengthened by providing ties and struts is known as Trussed Beams.
22. Distinguish between deck type and through type trusses.
A deck type truss is one in which the road is at the top chord level of the trusses. We
would not see the trusses when we ride on the road way. A through type truss is one in which
the road is at the bottom chord level of the trusses. When we travel on the road way, we would
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see the web members of the trusses on our left and right. That gives us the impression that we
are going through the bridge.
UNIT II
INFLUENCE LINES FOR DETERMINATE BEAMS
1. State Muller-Breslau principle.
Muller-Breslau principle states that, if we want to sketch the influence line for any force
quantity (like thrust, shear, reaction, support moment or bending moment) in a structure,
(i) We remove from the structure the resistant to that force quantity and
(ii) We apply on the remaining structure a unit displacement corresponding to that
force quantity. The resulting displacements in the structure are the influence line
ordinates sought.
2. State Maxwell-Betti‟s theorem
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In a linearly elastic structure in static equilibrium acted upon by either of two systems
of external forces, the virtual work done by the first system of forces in undergoing the
displacements caused by the second system of forces is equal to the virtual work done by the
second system of forces in undergoing the displacements caused by the first system of forces.
Maxwell Betti‘s theorem helps us to draw influence lines for structures.
3. What is the necessity of model analysis?
(i) When the mathematical analysis of problem is virtually impossible.
(ii) Mathematical analysis though possible is so complicatedand time consuming that
the model analysis offers a short cut.
(iii) The importance of the problem is such that verification of mathematical analysis by
an actual test is essential.
4. Define similitude.
Similitude means similarity between two objects namely the model and the prototype with
regard to their physical characteristics:
Geometric similitude is similarity of form.
Kinematic similitude is similarity of motion.
Dynamic and/or mechanical similitude is similarity of masses and/or forces.
5. State the principle on which indirect model analysis is based.
The indirect model analysis is based on the Muller Breslau principle. Muller Breslau
principle has lead to a simple method of using models of structures to get the influence lines
for force quantities like bending moments, support moments, reactions, internal shears, thrusts,
etc.
To get the influence line for any force quantity, (i) remove the resistant due to the force, (ii)
apply a unit displacement in the direction of the (iii) plot the resulting displacement diagram.
This diagram is the influence line for the force.
6. What is the principle of dimensional similarity?
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Dimensional similarity means geometric similarity of form. This means that all
homologous dimensions of prototype and model must be in some constant ratio.
7. What is Begg‟s deformeter?
Begg‘s deformeter is a device to carry out indirect model analysis on structures. It has the
facility to apply displacement corresponding to moment, shear or thrust at any desired point in
the model. In addition, it provides facility to measure accurately the consequent displacements
all over the model.
8. Name any four model making materials.
Perspex, plexiglass, acrylic, plywood, sheet araldite and bakelite are some of the
model making materials. Micro-concrete, mortar and plaster of Paris can also be used
for models.
9. What is „dummy length‟ in models tested with Begg‟s deformeter.
Dummy length is the additional length (of about 10 to 12mm) left at the
extremities of the model to enable any desired connection to be made with the gauges.
10. What are the three types of connections possible with the model used with Begg‟s
deformeter?
(i) Hinged connection (ii) Fixed connection (iii) Floating connection
11. What is the use of a micrometer microscope in model analysis with Begg‟s
deformeter?
Micrometer microscope is an instrument used to measure the displacements of
any point in the x and y directions of a model during tests with Begg‘s deformeter.
12. Define Indirect model Analysis.
Muller Breslau‘s principle is invaluable when applied to experimental methods. The
constraints selected by Muller Breslau can be actually implemented in a model and known
displacements applied at predicted points. We have to measure resulting displacements and plot
them to get the influence line.
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13. Write the examples for indeterminate beams.
Fixed beam
Continuous beam
Propped Cantilever
14. Why a structure is said to be indeterminate?
Indeterminate structures are series of connected elements used in building members like
beam, truss, and frames and will consist of additional elements not required for keeping the
structure stable.
Example of indeterminate structures is continuous beam, fixed beam, propped cantilever
beams, etc. The main factor that contributes to making a structure indeterminate is support
conditions (being fixed at ends, and continuous joints at member ends). A fixed end will have
three unknowns, and hinged end will have two unknowns). Indeterminacy can be classified
into static indeterminacy and kinematic indeterminacy.
15. Define kinematic redundancy. (N/D 2016, Apr/May2011)
When a structure is subjected to loads, each joint will undergo displacements in the form of
translations and rotations. Kinematic redundancy of a structure means the number of unknown
joint displacement in a structure.
16. Define static indeterminacy.
The excess number of reactions that make a structure indeterminate is called static
indeterminacy.
Static indeterminacy = No. of reactions – Equilibrium conditions.
17. What are the methods for constructing influence lines?
There are three methods used for constructing the influence line.
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The first is to tabulate the influence values for multiple points along the
structure, then use those points to create the influence line.
The second is to determine the influence-line equations that apply to the
structure, thereby solving for all points along the influence line in terms of
x, where x is the number of feet from the start of the structure to the point
where the unit load is applied.
The third method is called the Muller-Breslau principle. It creates a qualitative
influence line.
18. How will you create the influence line equations?
It is possible to create equations defining the influence line across the entire
span of a structure. This is done by solving for the reaction, shear, or moment at the
point A caused by a unit load placed at x feet along the structure instead of a specific
distance.
19. List the properties of influence lines for a statically determinate structure.
For a statically determinate structure the influence line will consist of
only straight line segments between critical ordinate values.
The influence line for a shear force at a given location will contain a
translational discontinuity at this location. The summation of the positive
and negative shear forces at this location is equal to unity.
Except at an internal hinge location, the slope to the shear force influence
line will be the same on each side of the critical section since the bending
moment is continuous at the critical section.
The influence line for a bending moment will contain a unit rotational
discontinuity at the point where the bending moment is being evaluated.
To determine the location for positioning a single concentrated load to
produce maximum magnitude for a particular function (reaction, shear,
axial, or bending moment) place the load at the location of the maximum
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ordinate to the influence line. The value for the particular function will be
equal to the magnitude of the concentrated load, multiplied by the ordinate
value of the influence line at that point.
To determine the location for positioning a uniform load of constant
intensity to produce the maximum magnitude for a particular function,
place the load along those portions of the structure for which the ordinates
to the influence line have the same algebraic sign. The value for the
particular function will be equal to the magnitude of the uniform load,
multiplied by the area under the influence diagram between the beginning
and ending points of the uniform load.
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60
61
62
63
64
65
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20. List the methods used for the analysis of fixed arches.
Strain energy method.
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Elastic centre method
Column analogy method.
UNIT IV - CABLES AND SUSPENSION BRIDGES
PART-A (2 marks)
1. Give any two examples of beams curved in plan. (Apr/May2011& 2016, N/D 2016)
Curved beams are found in the following structures.
Beams in a bridge negotiating a curve
Ring beams supporting a water tank
Beams supporting corner lintels
Beams in ramps
2. What is the nature of forces in the cables? (NOV/DEC 2017, Apr/May2011)
Cables of cable structures have only tension and no compression or bending.
3. Define tension coefficient. For what type of structures tension coefficient method is
employed? (AUC
Nov/Dec2011)(NOV/DEC 2017)
The tension coefficient for a member of a truss is defined as the pull or tension in
the member divided by its length, i.e. the force in the member per unit length.
4. What are the components of forces acting on the beams curved in plan and show the
sign conventions of these forces? (AUC Nov/Dec2011)
Beams curved in plan will have the following forces developed in them:
Bending moments
Shear forces
Torsional moments
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5. Define a space frame and what is the nature of joint provided in the space trusses?
(AUC May/June 2012)
A space frame is a structure built up of hinged bars in space. It is three dimensional
generalization of a truss.
Socket joint is provided in the space trusses.
6. What are the types of stiffening girders? (AUC May/June 2012)
Suspension bridges with three hinged stiffening girders
Suspension bridges with two hinged stiffening girders
7. What are the methods available for the analysis of space trusses? (AUC May/June
2013)
Tension co-efficient method is available for the analysis of space trusses.
8. What is the need for cable structures? (AUC May/June 2013)
The main load bearing member.
Flexible throughout.
It can take only direct tension and cannot take any bending moment.
9. What are cables structures? ( NOV/DEC 2012)
Long span structures subjected to tension and uses suspension cables for supports.
Examples of cable structures are suspension bridges, cable stayed roof.
Suspension bridge–
cable structure
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10. What is the true shape of cable structures?
Cable structures especially the cable of a suspension bridge is in the form of a catenary.
Catenary is the shape assumed by a string/ cable freely suspended between two points.
11. Mention the different types of cable structures.
Cable structures are mainly of two types:
(a)Cable over a guide pulley
(b)Cable over a saddle
12. Briefly explain cable over a guide pulley.
Cable over a guide pulley has the following properties:
Tension in the suspension cable =Tension in the anchor cable
The supporting tower will be subjected to vertical pressure and bending due
to net horizontal cable tension.
13. Briefly explain cable over saddle.
Cable over saddle has the following properties:
Horizontal component of tension in the suspension cable= Horizontal
component of tension in the anchor cable
The supporting tower will be subjected to only vertical pressure due to cable
tension.
14. What are the main functions of stiffening girders in suspension bridges? OR
Why are stiffening girders is used in suspension bridges?(April/may 2017 & 2015)
Stiffening girders have the following functions.
They help in keeping the cables in shape
They resist part of shear force and bending moment due to live loads.
15. Differentiate between plane truss and space truss.(Nov/Dec 2016)
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H2 V2
Plane truss:
All members lie in one plane
All joints are assumed to be hinged.
Space truss:
This is a three dimensional truss
All joints are assumed to be ball and socketed.
16. What are the significant features of circular beams on equally spaced supports?
Slope on either side of any support will be zero.
Torsional moment on every support will be zero
17. Give the expression for determining the tension T in the cable.
The tension developed in the cable is given by
T
Where, H=horizontal component and V= vertical component.
18. Define tension co-efficient. (Nov/Dec 2017)
The tension co-efficient for a member of a truss is defined as the pull or tension in
that member divided by its length.
19. What are cables made of?
Cables can be of mild steel, high strength steel, stainless steel, or polyester fibres.
Structural cables are made of a series of small strands twisted or bound together to
form a much larger cable.
Steel cables are either spiral strand, where circular rods are twisted together or
locked coil strand, where individual interlocking steel strands form the cable (often
with a spiral strand core).
Spiral strand is slightly weaker than locked coil strand. Steel spiral strand cables
have a Young's modulus, E of 150± 10kN/mm² and come in sizes from 3 to 90 mm
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diameter. Spiral strand suffers from construction stretch ,where the strands compact
when the cable is loaded.
20. Give the types of significant cable structures
Linear structures:
Suspension bridges
Draped cables
Cable-stayed beams or trusses
Cable trusses
Straight tensioned cables
Three-dimensional structures:
Bi-cycle roof
3D cable trusses
Tensegrity structures
Tensairity structures
21. What is a catenary?
Catenary is the shape taken up by a cable or rope freely suspended between
two supports and under its own self weight.
22. What is the degree of indeterminacy of a suspension bridge with two hinged
stiffening girder?
The two hinged stiffening girder has one degree of indeterminacy.
23. What are the forces developed in beams curved in plan?(May/June 2016)
Beams curved in plan will have the following forces developed in them:
Shear forces.
Bending moments.
Torsional moments.
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24. Give the expression for calculating equivalent UDL on a girder.
Equivalent UDLon a girder is given by:
25. Give the range of central dip of a cable.
The central dip of a cable ranges from 1/10 to 1/12 of the span.
UNIT V - PLASTIC ANALYSIS
PART-A (2 marks)
1. What is shape factor? (Nov/Dec 2017) (Apr/May2011) (Nov/Dec2011)
The shape factor is defined as the ratio of the plastic moment of a section to the
yield moment of the section.
Where Mp = Plastic moment
M= Yield moment
Zp= Plastic section modulus
Z= Elastic section modulus
2. State upper bound theorem. (Apr/May2011, Apr/May2011,
May/June 2013)
Upper bound theorem states that ―A load computed on the basis of an assumed
mechanism
is always greater than or equal to the true ultimate load‖.
3. Define plastic modulus. (N/D 2017,M/J 2014,M/J 2016,N/D 2011)
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The plastic modulus of a section is the first moment of the area above and below the
equal area axis. It is the resisting modulus of a fully plasticized section.
Zp= A/2(y1 +y2).
4. What are meant by load factor and collapse load? (AUC Nov/Dec2011&May/June
2012)
Load factor:
Load factor is defined as the ratio of collapse load to working load.
Load factor= collapse load working load
Collapse load: The load that causes the (n+ 1)the hinge to form a mechanism is called
collapse load where n is the degree of statically indeterminacy. Once the structure
becomes a mechanism.
5. Define plastic hinge with an example. (AUC May/June 2012& 2013)
When a section attains full plastic moment Mp, it acts as hinge which is called a
plastic hinge. It is defined as the yielded zone due to bending at which large rotations can
occur with a constant value of plastic moment Mp.
6. What is difference between plastic hinge and mechanical hinge?
Plastic hinges modify the behavior of structures in the same way as mechanical
hinges. The only difference is that plastic hinges permit rotation with a constant resisting
moment equal to the plastic moment Mp. At mechanical hinges, the resisting moment is
equal to zero.
7. List out the assumptions made for plastic analysis.(M/J 2016, A/M 2015)
The assumptions for plastic analysis are:
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Plane transverse sections remain plane and normal to the longitudinal axis
before and after bending.
Effect of shear is neglected.
The material is homogeneous and isotropic both in the elastic and plastic state.
Modulus of elasticity has the same value both in tension and compression.
There is no resultant axial force in the beam.
The cross-section of the beam is symmetrical about an axis through its centroid
and parallel to the plane of bending.
8. List out the shape factors for the following sections.
Rectangular section, S= 1.5
Triangular section, S= 2.346
Circular section, S= 1.697
Diamond section, S= 2
9. Mention the section having maximum shape factor.
The section having maximum shape factor is a triangular section, S= 2.345.
10. State lower bound theory.(N/D 2016,N/D 2016,M/J 2013,A/M 2015,A/M 2011)
Lower bound theory states that the collapse load is determined by assuming
suitable moment distribution diagram. The moment distribution diagram is drawn in such a
way that the conditions of equilibrium are satisfied.
11. What are the different types of mechanisms?
The different types of mechanisms are:
Beam mechanism
Column mechanism
Panel or sway mechanism
Cable mechanism
Combined or composite mechanism
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12. Mention the types of frames.
Frames are broadly of two types:
Symmetric frames
Un-symmetric frames
13. What are symmetric frames and how they analyzed?
Symmetric frames are frames having the same support conditions, lengths and
loading conditions on the columns and beams of the frame. Symmetric frames can be
analyzed by:
Beam mechanism
Column mechanism
14. What are unsymmetrical frames and how are they analyzed?
Un-symmetric frames have different support conditions, lengths and loading
conditions on its columns and beams. These frames can be analyzed by:
Beam mechanism
Column mechanism
Panel or sway mechanism
Combined mechanism
15. How is the shape factor of a hollow circular section related to the shape factor of a
ordinary circular section?
The shape factor of a hollow circular section =A factor K x shape factor of ordinary
circular section. SF of hollow circular section= SF of circular section x {(1–c3)/(1–c4)}.
16. Give the governing equation for bending.
The governing equation for bending is given by
M/I= /y
Where M=Bending moment
I =Moment of inertia
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σ = Stress
y=C.G.distance
17. Give the theorems for determining the collapse load.
The two theorems for the determination of collapse load are:
Static Method [Lower bound Theorem]
Kinematic Method [Upper bound Theorem]
18. What is a mechanism?
When an-degree indeterminate structure develops n plastic hinges, it becomes
determinate and the formation of an additional hinge will reduce the structure to a
mechanism. Once a structure becomes a mechanism, it will collapse.
19. What are the assumptions made in fully plastic moment of a section?
Plane traverse sections remain plane and normal to the longitudinal axis after
bending, the effect of shear being neglected.
Modulus of elasticity has the same value in tension and compression.
The material is homogeneous and isotropic in both the elastic and plastic
state.
There is no resultant axial force on the beam. i.e., total compression= total
tension.
The cross-section of the beam is symmetrical about an axis through its
centroid parallel to the plane of bending.
Longitudinal fibres are free to expand and contract without affecting the
fibres in the lateral dimension.
20. What are the limitations of load factor concept? (APRIL/MAY 2016)
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The analysis procedure does not give us any clue if a total loadWu/ load
factor the structure behaves well.
The stresses are within limit, so we have to check the stresses at crucial
points by conventional elastic method.
This is a peculiar and un realistic assumption.
The assumption of monotonic increase in loading is a simplistic.
CE 8602 - STRUCTURALANALYSIS-II
PART-B (13 Marks) & PART - C (15 Marks)
UNIT I - INFLUENCE LINES FOR DETERMINATE BEAMS
1. A system of four loads 80, 160, 160 and 120 kN crosses a simply supported beam of
span 25m with the 120 kN load leading. The loads are equally spaced at 1m. Determine
the values of the following using influence lines.
1. Maximum bending moment at a section 10m from left support and
2. Absolute maximum shear force and bending moment in the beam.
2. A beam has a span of 24m, draw the influence line diagram for the bending moment and
shear force at a section 8m from the left and also determine maximum bending moment
and shear force at this section due to two point loads of 10kN and 6kN at a fixed distance
of 2m apart rolling from left to right with 6kN load leading.
3. Two point loads of 100kN and 200kN spaced 3m apart cross a girder of span 12 meters
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from left to right with the 100kN leading. Draw the ILD for shear force and bending
moment and find the values of maximum bending moment and find the values of
maximum shear force and bending moment at a section 4m from the left hand support.
Also evaluate the absolute maximum bending moment due to the given loading system.
4. A simply supported beam has a span of 16m,is subjected to a UDL(dead load) of 5kN/m
and a UDL(live load) of 8kN/m(longer than the span) travelling from left to right. Draw
the ILD for shear force and bending moment at a section 4m from left end. Use these
diagrams to determine the maximum shear force and bending moment at this section.
5. A single rolling load of 100 kN moves on a girder of span 20m. (a) Construct the
influence lines for (i) shear force and (ii) bending moment for a section 5m from the left
support. (b) Construct the influence lines for points at which the maximum shears and
maximum bending moment develop. Determine these values.
6. Draw the ILD for shear force and bending moment for a section at 5m from the left
hand support of a simply supported beam, 20m long. Hence, calculate the maximum
bending moment and shear force at the section, due to a uniformly distributed rolling load
of length 8m and intensity 10 kN/m run.
7. A train of 5 wheel loads crosses a simply supported beam of span 22.5 m. Using
influence lines, calculate the maximum positive and negative shear forces at mid span and
absolute maximum bending moment anywhere in the span.
8. Four equal loads of 150 kN each equally spaced at 2m apart followed by a UDL of 60
kN/m at a distance of 1.5 m from the last 150 kN load cross a girder of 20 m span from
right to left.Using influence lines, calculate the shear force and BM at a section 8 m from
the left hand support when the leading 150 kN load is at 5 m from the left hand support.
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9. In a simply supported girder AB of span 2om, determine the maximum bending
moment and maximum shear force at a section 5m from A, due to the passage of a
uniformly distributed load of intensity 20 kN/m, longer than the span.
10. A warren girder of 25 metres span is made up of five panels of 5 m each. The
diagonals are inclined at 600 to the horizontal. Draw the influence line for the force in the
lower chord member in the second panel from left. Hence, evaluate the force in it when
there is a load of 100 kN at each lower joint.
UNIT II - INFLUENCE LINES FOR INDETERMINATE BEAMS
1. A continuous beam ABC is simply resting on supports A and C and continuous over the
support B. The span AB is 6 m and the span BC is 8 m. Draw the influence line diagram
for moment at B. Assume flexural rigidity is constant throughout and calculate the
influence line coordinates at 2 m intervals.
2. A continuous beam ABC is simply resting on supports A and C and continuous over the
support B and has an internal hinge (D) at 3 m from A. The span AB is 7 m and the span
BC is 10 m. Draw influence lines for reactions at A and B.
3. Using Muller Breslau principle, compute the ILD for reaction at A of the continuous
beam in figure at point D and E shown.
A 4 m D B 4 m E C
10 m 8 m
4. Using Muller Breslau principle, compute the ILD for (i) Reaction at B and (ii) Moment
at A for the propped cantilever shown in figure for a point 6.25 m from A.
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A B
L = 10 m
5. Determine the influence line for shear force at D, the mid-point of span BC of a
continuous beam shown in figure. Compute the IL ordinates at 1.5 m intervals.
A B D C
3 m
6m 6 m
6. Draw the influence line for MB for the continuous beam ABC simply supported at A
and C using Muller Breslau`s principle. AB=3m, BC=4m.EI is constant.
7. Draw the influence line diagram for the propped reaction of a propped cantilever beam
having span 6m. EI=Constant.
8. Determine the influence line diagram for bending moment at a point D, the middle point
of span AB of a continuous beam ABC of span AB=6m and BC=4m simply supported at
supports A,B and C. Compute the ordinates at every 1m interval.
9. Draw the influence line for RA for the continuous beam ABC of span AB = BC = 4m simply supported at A, B &C. Compute the ordinates at every 1m interval, EI= constant. 10. In a simply supported girder AB of span 2om, determine the maximum bending
moment and maximum shear force at a section 5m from A, due to the passage of a
uniformly distributed load of intensity 20 kN/m, longer than the span.
UNIT III - ARCHES
1. A circular three hinged arch of span 25m with a central rise of 5m is hinged at the
crown and the end supports. It carries a point load of 100 kN at 6m from the left support.
Calculate
i. The reaction at the supports
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ii. Moment at 5m from the left support.
2. A three hinged circular arch of span 16m and rise 4m is subjected to two point loads of
100 kN and 80 kN at the left and right quarter span points respectively. Find the reaction
at the supports. Find also the bending moment, radial shear and normal thrust at 6m from
left support.
3. A symmetrical three hinged arch has a span of 50 & rise 5m. Find the maximum
bending moment at a quarter point of the arch caused by a uniformly distributed load of
10kN/m which occupies any portion of the span. Indicate the position of the load for this
condition.
4. A three hinged parabolic arch of span 30m and rise 5m carries a uniformly distributed
load of 40kN per meter on the whole span and a point load of 200kN at a distance of 5m
from the right end. Find the horizontal thrust, resultant reaction, bending moment and
normal thrust at a section 5m from the left end.
5. A three hinged parabolic arch has supports at different levels having span 20m and
carries a UDL of 30kN/m over the left half of the span. The left support is 5m below the
crown and the right support is 4m below the crown. Draw the BMD. Also find the normal
thrust and radial shear at a section 4m from the left support.
6. A parabolic two hinged arch has a span of 40m and a rise of 5m. A concentrated load
10kN acts at 15m from the left support. The second moment of area varies as the secant of
the inclination of the arch axis. Calculate the horizontal thrust and reactions at the hinge.
Also calculate maximum bending moment at the section.
7. Evaluate the horizontal thrust in a two hinged parabolic arch of span 10m and rise 25m
carrying an UDL of 24 kN/m over the left half span, assuming secant variation of its
sectional moment of area. Also calculate the Bending Moment at the crown and draw the
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BMD.
8. Derive the expression for horizontal thrust in a two hinged parabolic arch carrying a
point load P at distance one fourth span from left support .Assume I=Io Secθ.
9. A two hinged parabolic arch of span L and rise h carries a triangular load covering a
distance a from the left end ,the intensity varying uniformly from zero to W. Obtain an
expression for the horizontal thrust.
10. Derive the expression for horizontal thrust in a two hinged semi circular arch of radius
R, carrying a point load W at the crown.
UNIT-IV CABLE AND SUSPENSION BRIDGES
1. A curved beam in the form of a quadrant of a circle of radius R and having a uniform
cross section is in a horizontal plane. It is fixed at A and free at B as shown in the figure.
It carries a vertical concentrated load W at the free end B. Compute the shear force,
bending moment and twisting moment values and sketch variations of the above
quantities. Also determine the vertical deflection of the free end B.
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2. A curved beam AB of uniform cross section is horizontal in plan and in the form of a
quadrant of a circle of radius R .The beam is fixed at A and free at B. It carries a
uniformly distributed load of w/unit run over the entire length of the beam as shown.
Calculate the shear forces, bending moment and Twisting moment value at A and B and
sketch the variations of the same. Also determine the deflection at the free end B.
3. Diagram shows a curved beam, semi-circular in plan and supported on three equally
spaced supports. The beam carries a uniformly distributed load of w/unit of the circular
length. Analyse the beam and sketch the bending moment and twisting moment diagrams.
4. A suspension cable having supports at the same level has a span of 30m and a
maximum dip of 3m.The cable is loaded with a udl of 10kN/m throughout its length. Find
the maximum tension in the cable.
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5. A suspension bridge of 250m span has two no‘s of three hinged stiffening girdness
supported by cables with a central dip of 25m.If 4 point load of 300kN each are placed at
the centre line of the roadway at 20, 30, 40 and 50m from the left hand hinge, find the
shear force and bending moment in each girder at 62.5m from each end. Calculate also the
maximum tension in the cable.
6. A suspension cable is supported at 2 points 25m apart .The left support is 2.5m above
the right support. The cable is loaded with a uniformly distributed load of 10kN/m
throughout the span. The maximum dip in the cable from the left support is 4m.Find the
maximum and minimum tensions in the cable.
7. A suspension cable of 75m horizontal span and central dip 6m has a stiffening girder
hinged at both ends. The dead load transmitted to the cable including its own weight is
1500kN.The girder carries a live load of 30kN/m uniformly distributed over the left half
of the span. Assuming the girder to be rigid, calculate the shear force and bending
moment in the girder at 20m from the left support. Also calculate the maximum tension
in the cable.
8. A suspension cable has a span of 120m and a central dip of 10m is suspended from the
same level at both towers. The bridge is stiffened by a stiffening girder hinged at the end
supports. The girder carries a single concentrated load of 100kN at a point 30m from left
end. Assume equal tension in the suspension hangers. Calculate
a. The horizontal tension in the cable
b. The maximum positive bending moment
9. A suspension cable of 40 m and 4m dip is stiffened by a three hinged girder.The dead
load is 15 kN m. determine the maximum tension in the cable and maximum BM in the
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girder dip to concentrated load of 80 kN crossing the girder, assuming that the whole dead
load is carried by the cable without stressing the girder.
UNIT-V PLASTIC ANALYSIS
1. Calculate the shape factor for a a) rectangle section of breadth ‗b‘ and depth ‗d‘,
b) Diamond section of breadth ‗b‘ and depth ‗d‘.
2. Calculate the shape factor for a triangle a) centroid lying at d/3 from the base of
depth‗d‘, and breadth ‗b‘. b) Circular section of dia‗D‘.
3. A mild steel I-section 200mm wide and 250mm deep has a mean flange thickness of
20mm and a web thickness of 10mm.Calculate the S.F. Find the fully plastic moment if
σy=252N/mm².
4. Find the shape factor of the I-section with top flange 100mm wide, bottom
flange150mm wide, 20mm tk and web depth 150mm and web thickness20mm.
5. Find the shape factor of the T-section of depth 100mm and width of flange
100mm,flange thickness and webthickness10mm.
6. A continuous beam ABC is loaded as shown .Determine the required Mp if the load
factor is 3.2.
7. A two span continuous beam ABC has span length AB=6m and BC=6m and carries
an udl of 30 kN/m completely covering the spans AB and BC.A and C are simple
supports. If the load factor is 1.8 and the shape factor is 1.15 for the I-section, find the
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section modulus; assume yield stress for the material as250N/mm².
8. Determine the collapse load for the frame shown in the diagram, Mp is the same for all
members.
9. Find the collapse load for the portal frame loaded as shown.
10. Find the collapse load for the loaded frame loaded as shown.
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V.S.B ENGINEERING COLLEGE, KARUR – 639 111
DEPARTMENT OF CIVIL ENGINEERING
CE8603 – IRRIGATION ENGINEERING
TWO MARKS QUESTIONS WITH ANSWERS
UNIT I - CROP WATER REQUIREMENT
1. Define Irrigation. (April/May 2011) (Nov/Dec 2012)
Irrigation is the process of supplying water to the soil by artificial means for the purpose
of supplement of the moisture essential for plant growth.
2. What are the necessities of irrigation? (Nov/Dec 2013)
a) Inadequate Rainfall
b) Uneven Distribution of rainfall
c) Growing a Number of Crops during a Year
d) Growing Superior Crops
3. What are the advantages of irrigation? (April/May 2011)
1. Increase in Crop Yield 9. Protection from Famine
2. Cultivation of Superior Crops 10. Elimination of Mixed Cropping
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3. General Prosperity of the Farmers 11. Increase in the Wealth of the Country
4. Generation of Hydro-electric Power 12. Domestic and Industrial Water Supply
5. Increase in the Wealth of the Country 13. Generation of Hydro-electric Power
6. Domestic and Industrial Water Supply 14. Inland Navigation
7. Canal Plantations 15. Increase in Ground Water Storage
8. Overall Development of the Country
4. What are the disadvantages of irrigation? (May/June 2012)
a) Water logging
b) Breeding Places for Mosquitoes
c) Unhealthy Climate
d) Salinity and alkalinity of land.
e) Ill aeration of soil.
f) Pollution of River Flows and Groundwater
g) Results in colder and damper climate causing outbreak of diseases like malaria.
5. What are the types of irrigation?
a) Surface irrigation.
b) Sub-surface irrigation.
c) Micro irrigation.
6. What are the techniques of water distribution in the farms?
a) Free flooding
b) Border flooding
c) Check flooding
d) Basin flooding, furrow irrigation method, drip irrigation method.
7. What are the types of sprinkler system?
a) Permanent system
b) Semi-permanent system
c) Portable system
8. What are the advantages of sprinkler irrigation?
a) Land levelling is not required
b) Fertilisers can be uniformly applied
c) It is less labour oriented
9. What are the limitations of sprinkler irrigation?
a) Initial cost of the system is very high
b) It requires larger electrical power
c) High wind may distort sprinkler pattern
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10. What is arid and semi-arid region?
The area where irrigation is must for agriculture is called arid region. The area in which
inferior crops can be grown without irrigation
11. Write Short notes on crop period, base period and rotation period. (Nov/Dec
2012)
Crop period: The time period that elapses from the instant of its sowing to the
instant of its harvesting is called crop period.
Base period: The time between the first watering of a crop at the time of its
sowing to its last watering before harvesting is called the base period. Crop period is
slightly more than the Base period.
Rotation period: The time interval between two such consecutive watering is called
frequency irrigation or rotation period.
12. Define duty of water.
It is the relationship between the volume of water and the area of crops it matures. It may
be defined as the number of hectares of land irrigated for full growth of a given crop by
supply of 1m3/sec of water continuously during the entire base period (B) of that crop.
13. Define delta of a crop.
Each crop requires a certain amount of water after a certain fixed interval of time, through
its period of growth. This total quantity of water required by the crop for its full growth
may be expressed in hectare-metre or simply as depth to which water would stand on the
irrigated area. This total depth of water (in cm) required by a crop to come to maturity is
called the delta (Δ).
Δ = 864 B
D (cm)
14. What are Kharif crops?
These are summer crops sown in April- May and harvested during September-October.
The kharif crops are rice, bajra, jawar, maize, cotton, tobacco, groundnut, etc. This is also
called as monsoon crops in areas, which are very much connected with southwest
monsoon.
15. What are Rabi crops?
These are winter crops sown in September-October and harvested during March-April.
Rabi crops are wheat, barley, gram, linseed, mustard, potatoes, etc
16. Define irrigation efficiency. (Nov/Dec 2011)
It is the efficiency of water output to the water input, and is usually expressed as
percentage. And the various irrigation efficiencies are
1. Efficiency of water-conveyance 3. Efficiency of water -storage
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2. Efficiency of water-application 4. Efficiency of use of water
17. What is transpiration?
Transpiration is the loss of water through the pores in the leaves of plants.
Transpiration ratio is the amount of water lost by a plant to the weight of solid matter
produced by the plant. This ratio varies crop to crop.
18. What are the factors affecting consumptive use/ water requirements? (Nov/Dec
2013)
1. Evaporation and the humidity 5. Depth of water applied
2. Average monthly temperature 6. Velocity of wind
3. Seasons of crop and crop pattern 7. Irrigation method
4. Monthly mean rainfall of the area
19. What is the scope of irrigation as far as engineering aspects are concerned?
Irrigation has to satisfy two aspects, viz, Engineering aspects and Agricultural aspects.
Engineering aspects comprises of
1. Finding water resources 5. Feeding of water to agricultural fields
2. Planning and construction of storage and
diversion works
6. Disposal of excess water by suitable
drainage system
3. Lifting water from ground water 7. Development of water power.
4. Conveying water to agricultural field
20. Define effective rainfall.
Precipitation falling during the growing period of a crop that is available to meet
the evapo- transpiration needs of the crop is called effective rainfall. It does not include
precipitation lost through deep percolation below the root zone or the water lost as surface
run off.
21. Define Crop rotation and Crop Ratio. (May/June 2013)
Crop Rotation: Method of growing different crops in the same field at different
times is natural and at the same time economical which is called rotation of crops. Thus
crop rotation is growing different crops one after the other in the same field in a year and
deriving the maximum benefit from the field.
Crop Ratio: The ratio of area irrigated in Rabi season to the area irrigated in Kharif
season is known as crop ratio.
22. What are the factors affecting duty?
1. Type of crop 6. Handling of water
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2. Type and level of land 7. Quality of water
3. Climate and season 8. Cultivation method
4. Useful Rainfall 9. Canal conditions
5. Length of Base period 10. Assessment of water supply
23. Differentiate between consumptive use and conjunctive use of water.
Consumptive use of a crop Conjunctive use of water
1. It may be defined as the total quantity of
water used by the crop, during its growth
period in transpiration and evaporation.
It means the water lifted from below the
ground is used in conjunction with canal
water. It is combination of ground water and
surface water.
24. Distinguish between evaporation and consumptive use.
Evaporation Consumptive use of a crop
1. It is the loss of water from water surfaces
which is a function of vapour pressure at
the water surface and the atmosphere above
it. Evaporation varies with the depth of
water.
It may be defined as the total quantity of
water used by the crop, during its growth
period in transpiration and evaporation.
25. What are the different types of duty and their units? (Nov/Dec 2010) (May/June
2012)
In direct irrigation, the duty is expressed as hectares/ cumec and the duty is called
flow duty.
In storage irrigation, the duty is expressed as hectares/million cubic metre of water
available in the reservoir and the duty is called Quantity duty or Storage duty.
26. What is mode of irrigation? (May/June 2013)
There are two broad modes of irrigation, viz., natural irrigation and artificial
irrigation.
Natural mode of irrigation is the one in which the object of irrigation is fulfilled without
involving any construction works of significance.
Artificial mode of irrigation is one wherein fields are irrigated after construction of properly
designed structures for storage and diversion works.
27. What is meant by Consumptive Irrigation Requirement (CIR)?
It is the amount of irrigation water required in order to meet the Evapotranspiration
needs of the crop during its full growth. It is nothing but the consumptive use itself, but
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exclusive of effective precipitation, stored soil moisture, or ground water. It can be written
as CIR = Cu - Re.
Where, Cu- Consumptive use, Re.- Effective Rainfall.
28. What is meant by Net Irrigation Requirement (NIR)?
It is the amount of irrigation water required in order to meet the evapotranspiration
needs of the crop as well as other needs such as leaching.
Therefore, NIR = Cu - Re + Water lost as percolation in satisfying leaching
UNIT 2- IRRIGATION METHODS
1. Write a short note on Lift irrigation with an example.
In lift irrigation water is lifted from a river or a canal to the bank to irrigate the land which is
not commanded by gravity flow. Lift irrigation is being increasingly practiced in India.
Irrigation from open well or tube well is a best example of lift irrigation, in which surface
water is lifted to top level and conveyed to the agricultural fields.
2. What is Lift area?
Lift area is defined as the area the level of which is too high to permit irrigation by gravity
flow from the source, but which can be irrigated by lifting water to the necessary level by
means of pump.
3. Write a short note on Tank irrigation.
A tank act as an irrigation storage system which is developed by constructing a small bund
of earth or stones built across a stream. Tank irrigation is more suitable in the peninsular
plateau area such as Andhra Pradesh (Including Telangana) and Tamil Nadu. According to
reports, Tamil Nadu has the second largest area which is over 23 per cent of tank irrigated
area of India and about one-fifth of the total irrigated area of the state.
4. What are the drawbacks of tank irrigation?
The drawbacks of tank irrigation are:
a) Major problem with tanks water storage is that tanks dry up during the dry season
and fail to provide irrigation when it is needed the most.
b) Tanks cover large areas of cultivable land.
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c) Lifting of water from tanks and carrying it to the fields is a tiring and expensive
effort which discourages the use of tanks as a source of irrigation.
5. Write a short note on well irrigation.
A well is a hole dug in the ground to get the subsoil water. Normal well is about 3-5 metres
deep but deeper wells up-to 15 metres are also dug. This system of irrigation has been used
in India from ancient time. Various methods are used to lift the ground water from the well
for irrigation, drinking, bathing and for other purposes. Well irrigation is more popular in
those regions where ground water is in ample and where there are few canals.
6. What is a tube well?
Tube well is a deeper well (generally over 15 metres deep) from which water is lifted with
the help of a pumping set operated by an electric motor, a diesel engine or solar power.
7. What are the disadvantages of well and Tube-well irrigation?
a) With these methods, only limited area can be irrigated.
b) Normally, a well can irrigate 1 to 8 hectares of land. The well may dry up and may
be rendered ineffective for irrigation if excessive water is taken out.
c) In the drought situation, the ground water level falls and enough water is not
available in the well when it is needed the most. Tube wells can draw a lot of groundwater
from its neighbouring areas and make the ground dry and not suitable for agriculture.
d) Well and tube well irrigation is not possible in areas of salty groundwater.
8. Write a short note on surface irrigation.
In this technique water flows and spreads over the surface of the land. Varied quantities of
water are allowed on the fields at different times. Therefore, flow of water under surface
irrigation comes under wobbly flow. Consequently, it is very difficult to understand the
hydraulics of surface irrigation.
9. What is micro-irrigation?
Micro irrigation is defined as the frequent application of small quantities of water directly
above and below the soil surface; usually as discrete drops, continuous drops or tiny streams
through emitters placed along a water delivery line.
10. Write a short note on irrigation scheduling.
Irrigation scheduling is the use of water management strategies to prevent over application
of water while minimizing yield loss due to water shortage or drought stress.
11. What do you meant by water user association (WUA)?
It is a self-managing group of farmers working together to operate and maintain their
irrigation and drainage network, to ensure fair and equitable water distribution, and to
increase crop yield.
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12. What is meant by Productivity?
Productivity is defined as the ratio of output and input. The output can be water delivered,
area irrigated, yield, or income, and the input can be water in the root zone, at the farm gate
at the outlet or at upstream points in the system including the point of diversion or storage.
Improved water supply influences the adoption of high – yielding agricultural practices by
farmers, which justify the productivity criterion of performance.
13. What are the main functions of Pani Panchayat?
The main functions of Pani Panchayat are:
a) To prepare cropping programme considering the soil and agro climatic condition
with due regards to crop diversification.
b) To prepare a plan for the maintenance of irrigation system in the area of its
operation at the end of each crop season and carryout the maintenance works with the funds
of the Pani Panchayats from time to time.
c) To regulate the use of water among the various pipe outlets under its area of its
operation according to the warabandi schedule of the system.
d) To promote economy in the use of water allocated.
14. What are the sub-systems present in any irrigation system?
a) The water supply sub-system which may include diversion from rivers or surface
ponds or pumped flow of ground water.
b) The water delivery subsystem which will include canals, branches and hydraulic
structures on these.
c) The water use subsystems, which can be one of the four main types, namely
Surface irrigation
Sub surface irrigation
Sprinkler irrigation
Trickle irrigation
d) The water removal system i.e, the drainage system.
15. List the various irrigation methods. (Nov/Dec 2012)
Irrigation water can be applied to croplands using one of the irrigation methods listed
below:
a) Surface irrigation which includes the following:
Uncontrolled flooding method
Border strip method
Check method
Basin method
Furrow method
b) Sub-surface irrigation
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c) Sprinkler irrigation
d) Trickle irrigation
16. How is the most suitable irrigation method selected?
Choice of the irrigation method depends on the following factors:
a) Size, shape and slope of the field
b) Soil characteristics
c) Nature and availability of the water supply subsystem
d) Types of crops being grown.
e) Initial development costs and availability of funds
17. Write a short note on furrow method of irrigation. (May/June 2013)
An alternative to flooding the entire land surface is to construct small channels along the
primary direction of the movement of water and letting the water flow through these
channels which are termed 'furrows'. Furrows are small channels having a continuous and
almost uniform slope in the direction of irrigation. Furrows are used to irrigate crops planted
in rows.
18. What are the disadvantages of furrow irrigation?
a) Possibility of increased salinity between furrows
b) Loss of water at the downstream end unless end dikes are used
c) The necessity of one extra tillage work viz., furrow construction
d) Possibility of increased erosion.
19. What are the conditions favoring sub-surface irrigation?
The conditions favoring sub-surface irrigation are:
(i) Impervious sub-soil at a depth of 2 m or more (ii) A very permeable sub-soil
(iii) A permeable loam or sandy loam surface soil (iv) Moderate ground slopes
20. Write short note on sprinkler irrigation
Sprinkling is a method of applying water to the soil surface in the form of a spray which is
somewhat similar to rain. In this method, water is sprayed to the air and allowed to fall to
the soil surface in a uniform pattern at a rate less than the infiltration rate of the soil.
21. What are the conditions favoring sprinkler irrigation? (May/June 2012) (Nov/Dec
2012)
The following conditions are favorable for sprinkler irrigation:
a) Very pervious soils that do not permit good distribution of water by surface
methods.
b) Lands which have steep slopes and easily erodible soils.
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c) Irrigation channels which are too small to distribute water efficiently by surface
irrigation.
d) Topography is irregular and Depth of soil is shallow over gravel or sand.
22. Explain the term water distribution.
Water distribution is the process of bringing water to consumers. It takes a number of forms
around the world from pressurized municipal water that delivers water directly into homes
to traveling tanker trunks that distribute water to community access points. Distribution of
water resources is usually overseen by a government agency, although private utilities may
also be involved.
23. Write short note on quality of irrigation water
Irrigation water must not have direct or indirect undesirable effects on health of humans,
animals and plants. The irrigation water must not damage the soil and not endanger the
quality of surface and ground waters with which it comes into contact. Attention is given to
the physical, chemical and biological characteristics of water.
24. Define long – term stability.
The long – term stability is defined as ―environmental stability‖ and ―durability‖ and refers
to the prevention or minimizing of adverse physical changes such as water logging, leaching
of nutrients form soils, salinity, erosion, silting, the ‗mining‘ of ground water, and
infestations with weeds.
25. What is a Tank irrigation method?
It is a storage irrigation method. This method utilizes the water stored on the upstream of a
small-size dam called bund. This simple reservoir is called a tank. Such tanks are present in
Southern part of India.
26. What is Contour farming? (May/June 2012)
Contour farming method comprises of conducting field operations such as
ploughing, planting and cultivating land across the slope instead of up and down hill. Here
curved plots, instead of regular sized plots are used with bunds formed following the
contours.
27. Recommend a suitable method of irrigation for a hilly terrain.
Hilly terrains have steep slopes where the conventional surface irrigation method
cannot be followed. In such cases contour farming method is adopted.
28. Name the components which are used in drip irrigation? (Nov/Dec 2011)
The components used in the drip irrigation system are
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1. Head 5. Sub-mains
2. Fertilizer tank 6. Laterals
3. Filter unit 7. Drip nozzles
4. Mains
29. What are the equipments used for lift irrigation?
Various equipments used for lifting water are:
1. Swinging basket 4. Pully
2. Archimedian screw 5. Mote
3. Denbli 6. Persian wheel bucket
30. Sate the site conditions in which drip irrigation is recommended to be adopted.
Drip irrigation is the latest field irrigation technique. It is recommended at places
where there exists acute scarcity of irrigation water and other salt problems. In this method
water is applied directly to the roots and hence there is no unwanted loss.
31. Why evaporation losses are less in furrow irrigation?
In this method only wetting of the field is done partly not fully as flooding method.
The wetted area is about 1/2 to 1/5 of the total area over which crops are grown. Further the
water just flows through field ditches called furrows. Because of these, there is a reduction
in loss of water due to evaporation, deep percolation, etc.
32. How is flow irrigation different from lift irrigation?
Surface irrigation is the supply of irrigation water to the land merely by the action of
gravity. Surface irrigations are (i) Flow irrigation and (ii) Lift irrigation. If the water is
available at a higher level the surface irrigation is effected by flow irrigation. If it is
available at a lower level and to be lifted by some mechanical means and then allowed to
flow by gravity is called lift irrigation.
33. What is wild flooding? (May/June 2013)
In this method water is flooded on an almost flat land which is not leveled earlier.
Thus water is forced to spread over vast tracks during the season of high stream flow. This
is the typical inundation irrigation system. Evidently it is waste of water and can be
encouraged in areas where there is abundant availability of water without high cost.
UNIT 3- DIVERSION AND IMPOUNDING STRUCTURES
1. What are impounding structures?
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Impounding structure" means a man-made structure, whether a dam across a watercourse or
other structure outside a watercourse, used or to be used to retain or store water or other
materials.
The term "impounding structure" shall not include: (a) dams licensed by the State
Corporation Commission that are subject to a safety inspection program; (b) dams owned or
licensed by the United States government; (c) dams operated primarily for agricultural
purposes which are less than twenty-five feet in height or which create a maximum
impoundment capacity smaller than 100 acre-feet; (d) obstructions in a canal used to raise
or lower water.
2. What is a gravity dam?
A gravity dam is a solid structure, made of concrete or masonry, constructed across a river
to create a reservoir on its upstream. The section of the gravity dam is approximately
triangular in shape, with its apex at its top and maximum width at bottom.
3. What are the forces acting on a gravity dam?
1. Weight of the Dam 5. Silt pressure
2. Water pressure 6. Wave pressure
3. Uplift pressure 7. Ice pressure
4. Seismic force 8. Wind pressure
4. Write short notes on (i) Storage head works (ii) Diversion head works
Storage head works: when a dam is constructed across a river valley to form a
storage reservoir, it is known as storage head works. The water is supplied to the canal form
this reservoir through the canal head regulator. Again this reservoir serves the multipurpose
functions such as hydro-electric power generation, flood control, fishery, etc..,
Diversion head works: when a weir or barrage is constructed across a perennial
river to raise the water level and to divert the water to the canal then it is known as a
diversion head works. The flow of water in the canal is controlled by canal head generator.
5. What are the points to be remembered while selecting the site for diversion head
works?
The following points should be remembered while selecting the site for diversion head
works:
a. At the site, the river should be straight and narrow.
b. The river banks should be well defined
c. The valuable land should not be submerged when the weir or barrage is constructed
d. The elevation of the site should be much higher that the area to be irrigated
6. What is a weir?
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Normally, the water level of any perennial river is such that it cannot be diverted to the
irrigation canal. That level of the canal may be higher than the existing water level of the
river. In such a case, weir is constructed across the river to raise the water level from H1 to
H2. Then, the water can be easily diverted to the canal. The surplus water passes over the
crest of the weir.
7. What is a divide wall?
The divide wall is a long wall constructed at right angles to the weir or barrage; it may be
constructed with stone masonry or cement concrete. On the upstream side, the wall is
extended just to cover the canal head regulator and on the downstream side it is extended
up to the launching apron.
8. What is a Barrage?
When the water level on the upstream side of the weir is required to be raised to different
levels at different times, then the barrage is constructed. Practically a barrage is on
arrangements are adjustable gates or shutters at different tiers over the weir. The water level
can be adjusted at H1, H2, etc. by operating the adjustable gates.
9. What are the functions of a divide wall ?
a) To form a still water pocket in front of the canal head so that the suspended silt can
be settled down which than later be cleaned through the scouring sluice from time to time.
b) It controls the eddy current or cross current in front of the canal head
c) It provides a straight approach in front of the canal head
d) It resists the overturning effect on the weir or barrage caused by the pressure of the
impounding water.
10. What are the functions of head works?
Functions of headworks may be identified as given below:
a) The rise of water level in the river is caused so as to increase the command area.
b) The flow of water into the canal is regulated.
c) The entry of silt into the canal is controlled.
d) Storage made is used for short periods at the time of short supplies.
11. Name the constituent parts of a Diversion headworks.
A Division Head works comprises of the following constituent parts,
1. Weir or Barrage
2. Canal Head Regulator
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12. Differentiate a weir from a barrage.
Weir Barrage
1. A weir is one which may have no
shutter/gate or the depth of gate is less than
the depth of pond made by construction of
crest.
A barrage is one which may have a small
height of crest and a tall shutter/ gate or a
full shutter with no crest for pond of water.
13. List the elements of a weir.
3. Divide wall
4. River training works
5. Scouring Sluice
6. Main Canal
7. Fish Ladder
8. Silt Regulation works.
1. Body wall of the weir
2. Crest of the weir
3. Shutter on crest of weir
4. Upstream talus
5. Upstream clay blanket
6. Upstream cut off
7. Upstream or force apron
8. Downstream or rear
apron
9. Downstream run off
10. Downstream inverted
filter
11. Downstream concrete
blocks
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14. Distinguish between a masonry weir and rock fill weir.
Masonry Weir Rock fill weir
1. Masonry weir consists of a horizontal
floor and masonry crest with the
downstream face vertical or nearly vertical.
Rock fill weir is mainly constructed by dry
rock fill with masonry retaining walls for
support.
2. Shutters are provided to store the water
up to the required level.
This type of weir is provided with sloping
aprons.
15. What are the static forces which act on weirs founded on impervious foundation?
Following are the static forces act on a weir founded on an impervious stratum.
a) Water pressure on the upstream side of the weir.
b) Water pressure on the downstream side of the weir.
c) Weight of water supported by the crest and the weight of the weir.
16. What are the factors to which a weir, founded on pervious foundation, is
subjected to?
The under forces acting on the weirs founded on pervious foundations are the
following:
a) Erosive forces due to the flow of water on the stream bed under the floor of the
weir.
b) Upward static pressure on the floor of the weir produced by the water flowing under
the floor.
12. Dwarf wall
13. Concrete floor
14. Downstream talus
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17. What are the forces considered with the design of Body wall of a weir?
The body wall is designed using the middle third rule. In order to avoid development of
tensile stresses, the resultant R of the hydrostatic forces Hh and Hv and the weight W of the
wall should be within the middle third of the base.
18. State the assumptions made in Bligh‟s theory.
a) Hydraulic slope or gradient is constant throughout the impervious length of the
apron.
b) Percolating water is to creep along the contact of the base profile of the apron with
the sub soil, losing head enroute proportional to the length of the level.
19. Write the uses of dams.
a) Protection of men and materials at the downstream aside during flood by storing the
excess flood waters.
b) Stored water is used for irrigation purposes.
c) In areas of ground water shortage, the stored water can be used as very good sources
for water supply.
d) If adequate head of water is available by storage, then it can be used for power
generation.
e) Serves as a means of navigation.
f) Forms an excellent base for breeding of fish because of continuous availability of
water.
g) Along with a green environment the dam location forms a place for recreation such
as boating, swimming, water skilling, etc.
h) Provides improvement in climate lessening of river pollution.
i) Reduction in river section of the downstream of the dam thereby making available
considerable land from river bed for cultivation.
20. What are the different types of dams? State their suitability.
Sl.No Types of dam Suitability
1. Gravity Dams
They require a strong foundation, preferably rock, to resist the
weight of the dam. Most suited across narrow gorges with steep
side slopes.
2. Arch Dams They require a strong abutment to resist the reaction and need less
mass. Suitable for narrow gorges and where the height is more.
3. Buttress Dams Less weight and suitable where rocky or hand stratum is not
available.
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4. Timber and Steel
Dams
Very less weight and a temporary structure and the height of dam
is restricted to 9 m.
5. Earth and Earth-
rock Dams
Considered where large quantity of suitable earth and rock
fragments are available and also in low bearing capacity sites.
21. List the factors which are to be considered in the selection of a dam site.
Various factors which are to be considered in the selection of a dam site are
grouped under seven major heads as detailed below:
1. Reservoir and catchment area 5. Materials of construction
2. Foundations 6. Economy
3. Topography 7. Environment
4. Location of spillway
22. Draw a typical line sketch of a gravity dam. Indicate the components.
23. State the stability requirements of a gravity dam.
Following are the stability requirements of a gravity dam:
a) Resultant of all forces on a horizontal plane at any level should lie within the middle
third of that horizontal section.
b) Maximum compressive stress at any level should be less than the safe compressive
strength of the material.
c) Dam should be safe against sliding.
d) Dam should be safe against overturning.
e) No tension should be created at any part of the dam or foundation.
24. How the top-width of a dam is decided?
Based on the requirement of work space the top width is provided. IS Code
recommends a minimum crest width of 6m. Crest width can be determined using the
following empirical formula.
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b = 𝐻
5 + 3 for very low dams
b = 0.55 𝐻 + 0.2 𝐻 for dams with H<30m
b = 1.65( 𝐻 + 1.5)1/3 for dams with H>30m
Where, H is the height of the dam (in metres)
25. What are the factors to be considered while deciding the earth dam section?
Following are the factors which have to be considered while deciding the earth
dam section:
a) Availability of construction material, their quantity and nearness to site.
b) Condition of foundation and cut off requirements
c) Types of construction machinery
d) Construction schedule and diversion considerations
e) Climate conditions and their interference in placement water content.
f) Safety requirements as regards to stability and seepage.
UNIT 4- CANAL IRRIGATION
1. What is a canal head regulator?
A structure which is constructed at the head of the canal to regulate flow of water is known
as canal head regulator. It consists of a numbers of piers which divide the total width of the
canal into a number of spans which are known as bays.
2. What are canal falls?
Generally, the slope of the natural ground surface is not uniform throughout the alignment.
Sometimes, the ground surface may be steep and sometimes it may be very irregular with
abrupt change of grade. In such cases, a vertical drop is provided to step down the canal bed
and then it is continued with permissible slope until another step down is necessary. This is
done to avoid unnecessary huge earth work in filling. Such vertical drops are known as
canal falls or simply falls.
3. What is the necessity for canal falls?
When the slope of the ground suddenly changes to steeper slope, the permissible bed slope
cannot be maintained. It requires excessive earthwork in filling to maintain the slope. In
such a case falls are provided to avoid excessive earth work in filling.
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4. Write short notes on cross-drainage works.
In an irrigation project, when the network of main canals, branch canals, distributaries, etc.
are provided, then these canals may have to cross the natural drainages like rivers, streams,
etc at different points within the command area of the project. The crossing of the canals
with such obstacle cannot be avoided. So, suitable structures must be constructed at the
crossing point for the easy flow of water of the canal and drainage in the respective
directions. These structures are known as cross-drainage works.
5. What is the necessity for cross drainage works?
The water-shed canals do not cross natural drainages. But in actual orientation of the canal
network, this ideal condition may not be available and the obstacles like natural drainages
may be present across the canal. So, the cross drainage works must be provided for running
the irrigation system. At the crossing point, the water of the canal and the drainage get
intermixed. So, far the smooth running of the canal with its design discharge the cross
drainage works are required.
The site condition of the crossing point may be such that without any suitable structure, the
water of the canal and drainage cannot be diverted to their natural directions. So, the cross
drainage works must be provided to maintain their natural direction of flow.
6. What are the common materials used for canal lining?
The commonly used materials for canal lining are :
a) Concrete
b) Rock masonry
c) Brick masonry
d) Bentonite-earth mixtures
e) Natural clays of low permeability
f) Different mixtures of rubble, plastic, and asphaltic materials.
7. Write short notes on concrete lining.
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Concrete lining is probably the best type of lining. Cement concrete lining made from
selected aggregate gives very satisfactory service. Despite the fact that they are frequently
high in their initial cost, their long life and minimum maintenance make them economical.
8. Write short notes on
(i) Bricks and Tiles lining (ii) Stone lining
(i) Bricks are installed in layers of two with about 1.25 cm of 1 : 3 cement mortar
sandwiched in between. Good quality bricks should be used. Brick tiles can be plastered to
increase the carrying capacity of canal with same section and help in increasing the life
span of the lining.
(ii) Stone lining of canals, if economically feasible, is useful for preventing erosion and
where the ground water level is above the bed of the canal and there is a possibility of
occurrence of damaging back pressures. The stones used for boulder linings should be hard,
durable, and capable of sustaining weathering and water action.
9. What are the drawbacks of Kennedy's theory?
Drawbacks of Kennedy‟s Theory are:
a) The theory is limited to average regime channel only.
b) The design of channel is based on the trial and error method.
c) The value of m was fixed arbitrarily.
d) Silt charge and silt grade are not considered.
e) There is no equation for determining the bed slope and it depends on Kutter‘s
equation only.
10. What are the drawbacks of Lacey's theory?
Drawbacks of Lacey‟s Theory are:
a) The concept of true regime is theoretical and con not be achieved practically.
b) The various equations are derived by considering the silt factor f which is not at all
constant.
c) The concentration of silt is not taken into account.
d) Silt grade and silt charge is not taken into account.
e) The equations are empirical and based on the available data from a particular type
of channel.
So, it may not be true for a different type of channel.
18. Compare Kennedy's and Lacey's theories.
KENNEDY'S THEORY LACEY'S THEORY
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1. It states that the silt carried by the flowing
water is kept in suspension by the vertical
component of eddies which are generated
from the bed of the channel.
It states that the silt carried by the flowing
water is kept in suspension by the vertical
component of eddies which are generated
from the entire wetted perimeter of the
channel.
2. In this theory, a factor known as critical
velocity ratio ‗m‘ is introduced to make the
equation applicable to different channels with
different silt grades.
In this theory, a factor known as silt factor ‗f‘
is introduced to make the equation applicable
to different channels with different silt grades.
19. Write short notes on Soil -Cement linings.
These linings are constructed using cement (15 to 20 per cent by volume) and sandy soil
(not containing more than about 35 per cent of silt and clay particles). Cement and sandy
soil can be mixed in place and compacted at the optimum moisture content. This method of
construction is termed the dry-mixed soil-cement method.
20. What are the factors to be considered before selecting the type of material for
lining?
a) Economy
b) Structural stability
c) Resistance to erosion
d) Durability
21. What is a permanent canal?
A permanent canal has a continuous source of water supply. Such canals are also known as
perennial canals.
22. What is an inundation canal?
This type of canal draws its supplies from a river only during the high stages of the river.
Such canals do not have any head works for diversion of river water to the canal, but are
provided with a canal head regulator.
23. Briefly explain the points to be considered for canal alignment.
a) An irrigation canal should be aligned in such a way that maximum area is irrigated
with least length of canal.
b) Cross drainage works should be avoided as far as possible, such that the cost is
reduced.
c) The off taking point of the canal from the source should be on a ridge, such that the
canal must run as a ridge canal and irrigate lands on both sides.
d) Sharp curves in canals must be avoided.
24. Briefly explain the problem in the design of unlined canals in alluvial soils.
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When water from the catchment or drainage basin enters the river it carries huge amounts
of silt or sediments along with it. The sediment is carried either in suspension or dragged
along the rivers bed. A portion of this silt or sediment also entire the canals. These
sediments can cause a problem in the design of unlined canals in alluvial soils.
25. What are the measures to be taken for improving the duty of irrigation system ?
a) The channel should not be in sandy soil and be as near the area to be irrigated as
possible so that the seepage losses are minimum value. Wherever justified, the channel may
be lined.
b) The channel should run with full supply discharges per the scheduled program so
that the farmers can draw the required amount of water in shorter duration and avoid the
tendency of unnecessary over -irrigation.
26. What is an aqueduct?
The hydraulic structure in which irrigation canal is passing over the drainage is known as
aqueduct. This structure is suitable when bed of canal is above the highest flood level of
drainage. In this case, the drainage water passes clearly below the canal.
27. What are the main functions of a cross-regulator?
The main functions of a cross-regulator are listed below:
a) To control the entire Canal Irrigation System.
b) To help in heading up water on the upstream side and to fed the off-taking canals to
their full demand.
c) To help in absorbing fluctuations in various sections of the canal system, and in
preventing the possibilities of breaches in the tail reaches.
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d) Cross regulator is often combined with bridges and falls, if required.
28. What are the non-structural measures for reducing water logging?
a) Adoption of tolerant crops.
b) Restricting canal supplies close to crop water needs.
c) Switch over to drip irrigation.
d) Conjunctive use of surface and ground water.
UNIT 5- WATER MANAGEMENT IN IRRIGATION
1. What are the problems of irrigation management without participatory
management? a) Inadequate water availability at the lowest.
b) Poor condition / maintenance of the system.
c) Lack of measuring devices and control structures.
d) Inadequate allocation for operation and maintenance.
e) Lack of incentives for saving water.
f) Poor drainage.
2. Write the methods used for controlling water logging?
The following measures may be taken to control water logging:
a) Prevention of percolation from reservoirs.
b) Control of intensity of irrigation.
c) Economical use of water.
d) Prevention of percolation from canals.
3. Define on-farm water management.
It can be defined as manipulation of water within the borders of an individual farm, a
farming plot or field. Example: in canal irrigation system, OFWM starts at the farm gate and
ends at the disposal point of the drainage water to a public watercourse, open drain or sink.
4. What is participatory irrigation management? (Apr/May 2008) (May/June 2012)
Participatory Irrigation Management (PIM) refers to a management approach that embraces
the involvement of the people who directly use the irrigation water i.e farmers.
5. What are the objectives of participatory irrigation management?
The objectives of PIM are:
a) To create a sense of ownership of water resources and the irrigation system among
the users, so as to promote economy in water use and preservation of the system.
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b) To improve service deliveries through better operation and maintenance.
c) To achieve optimum utilization of available resources through sophisticated
deliveries, precisely as per crop needs.
d) To achieve equity in water distribution.
6. What are the causes of water loss?
a) seepage from the canal
b) over irrigation of field
c) heavy surface runoff
7. What are ways of water loss in the canal?
a) seepage loss
b) evaporation loss
8. What are factors on which seepage loss depends?
a) Position of water table
b) Porosity of sub-soil
c) Porosity of soil
d) Extend of absorbing medium
9. What are two different condition of seepage?
a) Percolation
b) Absorption
10. How to minimize the irrigation water losses? (May/June 2009) (Nov/Dec 2012)
Irrigation water losses may be attributed to various factors such as conveyance losses,
seepage or absorption losses, evaporation losses, etc. Irrigation losses are minimized by,
a) Improving irrigation efficiency
b) Correct irrigation scheduling
c) Conversion of system of supply of water
d) Change of method of irrigation.
11. What are the advantages of irrigation water managements?
a) Achievement of optimum irrigation efficiency
b) Economical and efficient operation and maintanence of irrigation system
c) Equitable distribution of supplies to irrigators especially at the end
12. Discuss some components of water management?
a) Water shed management
b) Land management
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c) Rain water management
d) Reservoir management
13. What is the impact of water user association? a) Conveyance efficiency
b) Operation efficiency
c) Equity
d) Area water unit ratio
14. What are the advantages of water user association? (Apr/May 2008)
a) better maintenance of the distributaries
b) possibility of high value of crop programme
c) availability of water and irrigation process
15. What are optimizations of water user association?
a) To reduce the seepage loss and conveyance
b) Control over the usage of water
c) Planning
d) To avoid excess supply of water
16. What are the factors which influence evaporation loss?
a) Temperature
b) Wind velocity
c) Relative humidity
17. What is land management?
The intensity of raising productivity per unit area per unit time needs to be increased which
amounts to increasing cropped area.
18. What are the irrigation methods for cultivation?
a) Border strip-wheat
b) Furrow method –cotton
c) Basin method –orchard
19. What is meant by cad?
It abbreviated by Command area development. The concept of these developments is to
ensure efficient water utilization.
20. What are the uses of irrigation waters?
a) Wastages due to over irrigation
b) Wastages due to surface runoff
c) Wastages due to escape of water
21. What are works on farm development? (Nov/Dec 2008) (Nov/Dec 2008)
The items of works which are involved in the form water management are termed as On
Farm Development Works (OFD Works). The basic issues pertaining to design and
implementation of OFD works are:
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a) Design and execution sequence
b) Functional utility
c) Farmers participation
d) Organizational coordination.
22. What are the components of on farm developments?
a) Field drain
b) Crossing in field channel
c) Crossing of field channel
d) Formation of field channel
23. What are the needs of optimum use of water? (May/June 2007) (Nov/Dec 2008)
Optimum utilization of water for the crops yields the following results:
a) Prevents wastage of water
b) Prevents excessive soil erosion
c) Reduces labour and pumping cost
d) Improves scheduling techniques
e) Helps water delivery schedule
f) Improves the quality of crop.
13 MARKS QUESTIONS
UNIT I- CROP WATER REQUIREMENT
1) Explain the merits and demerits of irrigation in the present day. Also discuss the
environmental consequence of major irrigation project.
2) Explain the importance of crop rotation.
3) Briefly explain about irrigation efficiencies?
4) What do you meant by consumptive use of water? Explain the direct measurement of
consumptive use of water.
5) Briefly explain about planning and development of irrigation project?
6) Explain the necessity and scope of irrigation.
7) Define duty and explain in detail the various factors affecting duty. Derive the
relationship between duty, delta and base period.
8) Write the methods for improving duty.
UNIT 2- IRRIGATION METHODS
1. Briefly explain about canal irrigation?
2. Briefly explain about lift irrigation?
3. Briefly explain about tank irrigation?
4. Briefly explain about flooding methods?
5. Briefly explain about sprinkler irrigation methods?
UNIT 3- DIVERSION AND IMPOUNDING STRUCTURES
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1. What are the factors affecting location and types of dams?
2. Briefly explain about tanks, sluices and weirs?
3. What are types of dams and dam arches?
4. What are forces acting on a dam?
5. Explain the design features of cross drainage works?
UNIT 4- CANAL IRRIGATION
1. What is the necessity of river training works?
2. Describe in brief different types of river training works?
3. What is mean by guide banks? What are their functions and effects?
4. State the necessity and location of canal falls?
5. Briefly explain about classification of canals?
UNIT 5- WATER MANAGEMENT IN IRRIGATION
1. Briefly explain about on-farm-development works?
2. What is the need for water user‘s association?
3. What is the need for optimization of water use?
4. Briefly explain about percolation pond?
5. Discuss the role of farmers in water management?
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V.S.B ENGINEERING COLLEGE, KARUR
DEPARTMENT OF CIVIL ENGINEERING
CE 8604 - HIGHWAY ENGINEERING
TWO MARKS QUESTION BANK WITH ANSWERS
UNIT I - HIGHWAY PLANNING AND ALIGNMENT
1. What is meant by ―TRANSPORTATION‖?
Transportation engineering is a branch of engineering dealing with planning,
designing, estimation, construction, operation, maintenance, rehabilitation and
management of transportation infrastructure for movement of people and goods from
one place to the other safely, timely, conveniently, comfortably, economically by using
various modes like highways, railways, air ways, water ways and pipe ways also.
2. List out the modes of transportation.
Land, Water and Air.
3. What is the importance of Jayakar committee?
In the year 1927 the Indian Roads and Transport Development Association
(IRTDA) was set up with a view to study the transport problems of the country and
recommend improvement. At the recommendations of IRTDA, Mr. M.R.Jayakar was
appointed as the Chairman by the Central Government for a committee to look into the
road development in India and submit a report. This committee is generally referred to
as Jayakar committee.
4. What are the objectives of Central Road Fund?
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As per the recommendations of Jayakar Committee a ―Central Road Fund‖ was
created in 1st March 1929. The consumers of petrol were then charged an extra levy of
2.64 paise per litre. Twenty percent of the revenue collected through the fund was
retained as Central Reserve and the balance allotted to the various states based on the
actual petrol consumptions.
5. What are the objectives of Indian Road Congress?
1. To promote and encourage the science and practice of construction and
maintenance of roads.
2. To suggest improved methods of administration, planning design,
construction, operation, use and maintenance of roads.
3. To promote the use of standard specifications and to propose specifications.
4. To advise regarding education, libraries, research connected works, like
publication, etc.
6. What are the main factors for consideration in third twenty year road development
programme?
1. Growth of Industry and agriculture
2. Requirements of hills, deserts and coastal areas
3. Expansion of tourism
4. Rural and Urban development
5. Environmental consideration
7. Write a short note about National Transport Policy Committee.
1. It was formed by central government in 1978 to prepare a comprehensive
national transport policy for the country.
2. Report was submitted in 1980.
3. Major recommendations in the report are accepted by central
government..VIDYARTHIPLUS.COM
4. Some important recommendations are regarding strengthening of
existing
5. NH‘S, development plans, maintenance of NH, funds required for
development.
8. What are the objectives of highway research board?
1. To collect and analyze results on research
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2. To coordinate and conduct the correlation services in transport research
3. To evaluate the nature and extend of research required.
4. To regulate the conductive services
9. State the names of various patterns of the road.
1. Rectangular or block pattern
2. Radial or star block pattern
3. Radial or star circular pattern
4. Radial or star grid pattern
5. Hexagonal pattern
6. Minimum travel pattern
10. Mention the functions of medians in urban roads.
1. To avoid the head-on collision between vehicles moving in opposite
direction
2. To channelize the traffic in to streams at intersections
3. To provide protection for pedestrians
4. To separate slow moving traffic
11. What is BOT project?
1. BOT means Build, Operate and Transfer.
2. It is public private partnership model where a private organization is given
responsibility of construction and operation of roads and then the control
is transferred to the government. .VIDYARTHIPLUS.COM
12. How length of National Highways has to be computed as per 3rd
road development
plan?
1. As per 3rd
road development plan, the National Highways are designed
based on the concept of 1km length per 50 sq.km area.
2. Hence the total length of NH in an area can be calculated by dividing the
total area by 50.
13. What is the objective of highway planning?
1. To create awareness of unforeseen events changed policies and other
current developments.
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2. To prepare a plan in such a way that traffic operations are carried out
efficiently.
3. To assist the general planner for serving what transportation demands.
14. Define the role of IRC.
Indian Road Congress (IRC) was constituted to provide a forum for regular
pooling of experience and ideas on all matters affecting the planning construction and
maintenance of roads in India.
15. Define the main objectives of CRRI
1. To carry out the basic and applied research for investigation, design,
construction and maintenance of different types of roads and runways.
2. To carry out research on road traffic and transportation, including traffic
safety and transport economics.
3. To render technical advice and consultancy services to various
organizations.
16. What are the classifications of urban roads?
1. Arterial roads
2. Sub-arterial roads
3. Collector roads and
4. Local roads.
17. What are the different classifications of roads according to Nagpur road plan?
1. National highways (NH)
2. State highways (SH)
3. District highways (DH)
4. Major district roads (MDR)
5. Other district roads (ODR)
6. Village roads (VR)
18. List twenty-year road development plans.
1. Nagpur plan (1941 -61)
2. Bombay plan (1961 -81)
3. Road development plan (1980 -2001)
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4. Road development plan (2001 -2021)
19. What are ideal alignment and its requirements?
The course or position of the centre line of the highway on ground is called
highway alignment Requirements: Short, Easy, Safe and Economical.
20. What is road ecology?
Road ecology is a relatively new sub discipline of ecology that focuses on
understanding the interactions between road systems and the natural environment.
21. What are the factors controlling highway alignment?
1. Obligatory points
2. Traffic
3. Geometric design
4. Economics
5. Other considerations
22. Define obligatory point.
The controlling points which govern the highway alignment are known as
obligatory points and they are mainly responsible for the deviation of highway from its
straight location.
UNIT II - GEOMETRIC DESIGN OF HIGHWAYS
1. What do you understand by geometric design?
The geometric design of highway deals with the dimensions and layout of
visible features of the highway such as alignment sight distance and intersections. The
geometrics of highway should be designed to provide optimum efficiency in traffic
operations.
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2. What are the elements in Geometric design?
1. Cross section elements
2. Sight distance considerations
3. Horizontal alignment details
4. Vertical alignment details
5. Intersection elements
3. Define right of way.
RoW is the area of land acquired for the road along its alignment. The width of
this acquired land is known as land width and its depends on the importance of the
road and possible future development.
4. Define camber.
Camber (or) cross slope is the slope provided to the road surface in the
transverse direction to drain off the rain water from the road surface.
5. Define carriage way or width of pavement.
The pavement or carriage way width depends on the width of traffic lane and
number of lanes. The carriage way intended for one line of traffic movement may be
called a traffic lane.
6. What is mean by sight distance?
Sight distance available from a point is the actual distance along the road
surface. Which a driver from a specified height above the carriage way has visibility of
stationary or moving objects. In other words sight distance is the length of road visible
ahead to the driver at any distance.
7. Define SSD.
Stopping sight distance is also called non-passing sight distance. SSD is the
minimum sight distance available on a highway at any spot having sufficient length to
enable the driver to stop a vehicle travelling at design speed, safely without collision in
event of any obstruction.
8. Define passing sight distance or OSD.
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Overtaking sight distance is also called passing sight distance. Overtaking
Sight Distance is the minimum distance open to the vision of the driver of a vehicle
intending to overtake the slow moving vehicle ahead safely against the traffic in
opposite direction.
9. What are the factors affecting sight distance?
1. Reaction time of the driver
2. Speed of the vehicle
3. Efficiency of brakes
4. Frictional resistance between the tyre and the road
5. Gradient of the road
10. What is PCU?
PCU is passenger Car Unit. For traffic analysis, all vehicles are converted to
car by multiplying with their PCU value.
Eg: PCU for Bus - 3, two wheeler - 0.75.
11. Define traffic density.
Traffic density is defined as the number of vehicles occupying a unit length of
roadway at a given instant and is expressed in vehicles per kilometer.
12. Define Super elevation.
To counteract the effect of centrifugal force and reduce the tendency of the
vehicle to overturn or skid, the outer edge of the pavement is raised with respect to
the inner edge, thus providing a transverse slope throughout the length of the
horizontal curve. This transverse inclination to the pavement surface is known as
super elevation.
13. What are the four parts of PIEV theory?
1. Perception
2. Intellection
3. Emotion
4. Volition
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14. What is total reaction time?
Reaction time of the driver is the time taken from the instant the object is
visible to the driver to the instant the brakes are effectively applied. The total reaction
time may be split up into two parts:
Perception time and Brake reaction time
15. What is setback distance?
Setback distance or the clearance distance is the distance required from the
centerline of a horizontal curve to an obstruction on the inner side of the curve to
provide adequate sight distance at a horizontal curve.
16. What are the factors affecting the design of curve?
1. Design speed of the vehicle
2. Allowable friction
3. Maximum allowable super elevation
4. Permissible centrifugal ratio
17. What is meant by extra widening at curves?
Extra widening refers to the additional width of carriageway that is required on
a curved section of a road over and above that required on a straight alignment.
18. Define gradient.
Gradient is the rate of rise or fall along the length of the road with respect to
the horizontal. It is expressed as a ratio of 1 in X. Sometimes the gradient is also
expressed as a percentage.
19. Define limiting gradient.
This gradient is adopted when the ruling gradient results in enormous increase
in cost of construction. On rolling terrain and hilly terrain it may be frequently
necessary to adopt limiting gradient. But the length of the limiting gradient stretches
should be limited and must be sandwiched by either straight roads or easier grades.
20. Define vertical curves and categories of vertical curves?
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The vertical alignment of highway is necessary to introduce vertical curve at
the intersections of different grades to smoothen out the vertical profile and thus ease
off the change in gradient for the fast moving vehicles.
Categories: (i) Summit or Crests curves, and (ii) Valley or sag curves
UNIT III - DESIGN OF FLEXIBLE AND RIGID PAVEMENTS
1. Define pavement.
Highway pavement is a structure consisting of superimposed layers of
processed materials above the natural soil sub-grade, whose primary function is to
distribute the applied vehicle loads to the sub-grade.
The pavement structure should be able to provide a surface of acceptable
riding quality, adequate skid resistance, favourable light reflecting characteristics,
and low noise pollution.
2. What is rigidity factor in design for highway pavement?
The ratio of contact pressure to the tyre pressure is called Rigidity Factor.
3. Define ‗ESWL‘ (Equivalent Single Wheel Load).
Equivalent Single Wheel Load (ESWL) is the single wheel load having same
contact pressure which produces the same value of maximum stress, deflection, tensile
stress or contact pressure at desired depth.IDYARTHIPLUS.COM
4. How do you calculate the ESWL at a given depth below the pavement for a dual
wheel assembly?
ESWL for any depth can be calculated using the following formula.
At any depth greater than 2S, the stress due to dual wheel is considered to be
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equivalent to a single load of magnitude 2P.
5. Define rigid pavement.
Rigid Pavement is defined as the highway pavements with high flexural
strength, against the action of loads. These are made of cement concrete and pre-
stressed concrete slabs.
6. What is meant by flexible pavements?
Flexible pavements are those, which on the whole have low or negligible flexural
strength and are rather flexible in their structural action under the loads. The flexible
pavements layer reflects the deformation of the lower layers on to the surface of the
layer.
7. What are the factors affecting stability of pavement?
1. Traffic factors
2. Moisture factors
3. Climatic factors
4. Soil factors
5. Stress dissipation factors
8. What are the components in flexible pavements?
A typical flexible pavement consists of four components
1. Soil sub grade
2. Sub base course
3. Base course
4. Surface course
9. State the function of wearing course.
1. To provide a smooth surface for the traffic
2. To drain away rain water
3. To act as a cushion between the wheels and base
4. To provide resistance against wear and tear
10. Compare flexible and rigid pavements
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Flexible pavement Rigid Pavement
(i) Deformation in the sub grade is
transferred to the upper layers
(ii) Design is based on load distributing
characteristics of the component
layers
(iii) Have low Flexural strength
(iv) Load is transferred by grain to grain
contact
(v) Have low completion cost but
repairing cost is high
(vi) Have low life span
(i) Deformation in the sub grade is not
transferred to the subsequent layers.
(ii) Design is based on flexural strength
or slab action.
(iii) Have high Flexural strength
(iv) No such phenomenon of grain to
grain load transfer exists.
(v) Have low repairing cost but
completion is high
(vi) Have high life span
11. What are the factors considered in design of pavements?
The various factors to be considered for the design of pavements are given below
1. Design wheel load
2. Sub grade soil
3. Climatic factors
4. Pavement component materials
5. Environment factors
6. Special factors in the design of different types of pavements.
12. What are the drawbacks of CBR method?
1. Same design procedure is used for dual carriageway and multi-lane single
carriageway and there is no difference in design procedure for them.
2. The design curve provides only the total thickness of the pavement and did
not specify the thickness of sub base, base and surface separately.
3. The design permits the equivalency factor of up to 2 for flexible pavement.
it is not the suitable design of various bases and each one need to be
evaluated.
13. What are the tests available to evaluate the soil strength?
1. CBR test
2. CRV test
3. Tri-axial compression test
4. Plate-bearing test.
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14. What are the factors considered in design of pavement?
1. Design wheel load
2. Sub grade soil
3. Climatic factors
4. Pavement component materials
5. Environmental factors
6. Special factors in the design of different types of pavements.
15. Define critical load positions.
Since the pavement slab has finite length and width, either the character or the
intensity of maximum stress induced by the application of a given traffic load is
dependent on the location of the load on the pavement surface.
16. What are the types of loading?
1. Interior loading: When load is applied in the interior of the slab surface
2. Edge loading: When load is applied in an edge of the slab
3. Corner loading: When the centre of the load application is located on the
bisector of the corner angle formed by two intersecting edges of the slab.
17. What types of join provided in cement concrete pavement?
1. Expansion joint
2. Contraction joint
3. Warping joint
18. Write the importance of California bearing ratio?
1. It is the best suitable method for evaluating the stability of soil sub grade
and other flexible pavement materials.
2. The test results have been correlated, for highways and sir fields.
19. Define Embankment.
It is required to raise the grade line of a highway above the existing ground
level it becomes necessary to construct embankments.
The design elements in embankment are
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1. Height
2. Fill material
3. Settlement
4. Stability of foundation
5. Stability of slopes
20. Discuss about the temperature and warping stresses.
Temperature stresses are developed in cement concrete pavement due to
variation in slab temperature. During the day, the top of the pavement slab gets heated
under the sunlight when the bottom of slab still remains colder.
Warping stresses, whenever the top and bottom surface of a concrete pavement
possess different temperature, the slab tends to wrap downward or upward including
warping stresses.
UNIT IV - HIGHWAY CONSTRUCTION MATERIALS AND PRACTICE
1. What are the desirable properties of soil?
1. Stability
2. Incompressibility
3. Permanency of strength
4. Minimum changes in volume and stability
5. Good drainage
6. Ease of compaction
2. What is the use of plate bearing test?
1. The plate bearing test is used to evaluate the supporting power of sub grade
for use in pavement design by using relatively large diameter plates.
2. The plate bearing test was originally devised to find the modulus of sub
grade reaction in the Westergaard‘s analysis for wheel load stress in
cement concrete pavements.
3. What are the desirable properties of aggregates?
1. Strength
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2. Hardness
3. Toughness
4. Durability
5. Shape of aggregates
6. Adhesion with bitumen
4. What are the important functions of pavement?
1. To distribute the traffic load over the sub-grade soil.
2. To provide good riding surface.
3. To protect the sub-grade from climatic effects.
5. What are the limitations of C.B.R test?
1. It cannot be used to evaluate the soil properties like cohesion or angle of
internal friction or shearing resistance.
2. Materials passing through 20mm sieve can only be used for this test.
3. If the test sample consists of coarse grained particles, then obtained results
are not so suitable for proper designing of pavements.
W.RTHIPLUS.COM
6. Define ‗Flakiness Index‘.
Flakiness index is defined as the percentage by weight of particles whose least
dimension/thickness is less than 3/5th
or 0.6 of their mean dimension. It can be
measured by using thickness gauge.
7. Define ‗Elongation Index‘.
Elongation index is defined as the percentage by weight of particles whose
greatest dimension or length is greater than 1 4/5th
or 1.8 times their mean dimension.
It can be calculated by using length gauge.
8. Define flaky aggregates.
Angular aggregates and their thickness are small, when compared to their width or
length is called Flaky aggregates. Eg: Laminate rocks.HIPLUS.COM
11. Differentiate between prime coat and tack coat in bituminous construction.
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Prime Coat Tack Coat
Applied to create bonding between
base layer and bitumen layer
Applied to create bonding
between bitumen layers.
Application of low viscosity cut
backs as primer on existing base
layer
Application of low viscosity
liquid bitumen to an existing
bituminous layer
Sprayed at an uniform rate of 7.3kg
to 14.6 kg per 10 sq.m
Sprayed at an uniform rate of 5kg to
10kg per sq.m
Rate of spraying depends on
porosity of the surface
Rate of spraying depends on the type
of the surface
12. What is the purpose of applying prime coat?
1. To plug the capillary voids and to act as a water proofing agent for
existing base.
2. To provide best bonding between existing granular layer and new bitumen
layer.
13. Why joints are provided in rigid pavements?
1. To absorb the expansion and contraction due to change of temperature.
2. To avoid warping of concrete slab at edges.
3. To provide continuity for concrete laying.
14. What are the requirements of ideal joints?
1. Should be easy to maintain
2. Moves freely without stress development
3. Should not allow infiltration of water
4. Should be convenient to road users.
5. Should be in level with the surface .VIDYARTHIPLUS.COM
15. Differentiate between tar and bitumen
Factors Tar Bitumen
Source Obtained from destructive
distillation of coal or wood
Derived from naturally
occurring petroleum
Solubility Soluble in carbon-disulphide
and carbon tetrachloride Soluble only in toluene
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Colour Black Black or brownish black
16. What is cutback bitumen?
Cutback is the materials in which the viscosity of bitumen is reduced by volatile
diluents. The distillates used for preparation of cutback bitumen are naphtha, kerosene,
diesel oil, and furnace oil. There are different types of cutback bitumen like rapid curing
(RC), medium curing (MC), and slow curing (SC).
17. Define emulsion.
Emulsion is when bitumen is suspended in a finely divided condition in an aqueous
medium and stabilized with an emulsifier. The bitumen content in the emulsion is around
60% and the remaining is water.
18. Write short notes on Modified bitumen.
Certain additives or blend of additives called as bitumen modifiers can improve
properties of bitumen and bituminous mixers. Bitumen treated with these modifiers is
known as modified bitumen. Polymer modified bitumen should be used only in wearing
course depending upon the requirements of extreme climatic variations.
19. Define highway drainage and its types.
Highway drainage is the process of removing and controlling excess surface and
subsoil water within the right of way.
Types: (i) Surface drainage, and (ii) Sub surface drainage
20. What materials used as joint filler?
1. Soft wood
2. Impregnated fiber board
3. Cork or Cork bound with bitumen
4. Coir fiber
UNIT V - EVALUATION AND MAINTENANCE OF PAVEMENTS
130
1. What are the reasons for the pavement defects?
1. Increase in traffic
2. Environmental changes
3. Design and construction deficiencies
4. Maintenance deficiencies
2. What are the reasons for development of edge cracks in flexible pavements?
1. Poor drainage
2. Inadequate lateral support
3. In-sufficient pavement width
3. Define plastic deformation
If applied stress is excessive than the stability of sub grade and if the plastic flow
takes place, then it is called plastic deformation.
4. Define Warping
Warping is the bending of the concrete slab due to uneven expansion or contraction
of top and bottom slab surfaces. It is caused by any differences in temperature above and
below the slab or caused by moisture differences.
iii. What are the reasons for disintegration of flexible pavement?
1. Improper mix design
2. Heavy rainfall or moisture content
3. Poor construction and poor materials
4. Poor compaction
5. Insufficient binder
6. What is unevenness index?
Unevenness index is defined as the cumulative measure of vertical undulations of
the pavement surface, recorded per unit length of the road. It can be measured by using
Bump Integerator.
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7. What is mud pumping?
1. Mud pumping is the rigid pavement failure
2. It happens when water is infiltrated through the cracks, joints and edges of
the rigid pavement.
3. The water will form soil slurry and it gets ejected when heavy load passes
through the cracks or joints.
8. What is spalling in rigid pavement?
Spalling is the breakdown or disintegration of slab edges at joints or at cracks or
directly over the reinforcing steel and generally due to the breakdown of pavement joint
edges from traffic action.
9. What are the causes of scaling?
Over vibration of concrete and Presence of chemical impurities
10. What is mud-jacking?
Mud-jacking is the repairing method of c.c or rigid pavements, in which the raising
of settled cement concrete slab or filling a void beneath the slab is done with cement grout.
11. State the remedial measures in rigid pavement for edge cracks.
1. Application of sealants
2. Application of epoxy resin
3. Proper designing method
12. What are the general problems in Earthern roads?
1. Formation of ruts in longitudinal direction along the wheel path of slow
moving vehicles.
2. Formation of dust in dry weather. W.VIDYARTHIPLUS.COM
13. Mention the types of skidding.
1. Straight skidding
2. Impending skidding
3. Sideway skidding
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14. Define pavement roughness index.
Pavement roughness index is defined as the grading of irregularities in the
pavement surface that adversely affect the riding quality of a vehicle. It is used to prepare
the guidelines for measuring roughness on a standard scale.
15. What is pavement serviceability?
It is defined as the evaluation of pavement in terms of surface unevenness,
patching and cracking etc., It is used to analyze the riding quality of pavement.
16. Differentiate Pumping and Raveling.
Pumping Raveling
The ejection of water and fine
materials under pressure through
cracks under moving loads.
The wearing away of the pavement
surface caused by the loss of binder or the
dislodging of aggregate particle or both.
17. What are the failures in rigid pavement?
1. Scalling of cement concrete
2. Shrinkage cracks
3. Spalling of joints
4. Warping cracks
5. Mud pumping
6. Structural cracks
18. Give some typical flexible pavement failures?
1. Alligator cracking
2. Consolidation of pavement layers
3. Shear failure
4. Longitudinal cracking
5. Frost heaving
6. Lack of binding
7. Reflection cracking
8. Formation of waves and corrugation
19. What is FWD and state its use?
133
A falling weight deflectometer (FWD) is a testing device used to evaluate the
physical properties of pavement. FWD data is primilarily used to estimate pavement
structural capacity for overlay design and to determine if a pavement is being overload.
FWD is used in highways, local roads, airport pavements, harbor areas and railway tracks.
20. What is Alligator crack?
Alligator cracks are caused by the repeated application of heavy wheel loads
resulting in fatigue failure or due to the moisture variations resulting in swelling and
shrinkage of sub grade and other pavement materials.
V.S.B ENGINEERING OLLEGE, KARUR
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DEPARTMENT OF CIVIL ENGINEERING
CE 8604 - HIGHWAY ENGINEERING
13 MARKS QUESTIONS BANK
UNIT 1- HIGHWAY PLANNING AND ALIGNMENT
1. History of highway development in India. (13mark)(University repeated
questions)
2. Soil suitability analysis. (8 mark)
3. National level institution in highway (IRC, CRRI,MORTH,NHAI,HRB)
(8 mark)(University repeated questions)
4. Factors influencing in highway alignment. (8 mark)
5. Modal limitations towards sustainability. (8 mark)
6. Conventional methods (old method) and non- conventional methods (modern
method)
(13mark)(University repeated questions)
7. Ideal alignment and requirements. (8 mark) (University repeated questions)
8. Classification of highways. (8mark)
UNIT 2 - GEOMETRIC DESIGN OF HIGHWAY
1. Typical Cross sectional elements. (8mark) (University repeated questions)
2. Super elevation derivation. (8 mark) (University repeated questions)
3. Sight distance and types. (8 mark) (University repeated questions)
4. Super elevation problem. (8 mark)
5. Overtaking sight distance problem (OSD)(8 mark) (University repeated
questions)
6. Stopping sight distance problem (SSD). (8 mark)
7. Extra Widening (Mechanical and psychological widening) (8 mark)
8. Length of valley curve. (8 mark) (University repeated questions)
9. Consideration for hill roads - Hairpin bends. (8 mark) (University repeated
questions)
10. Lateral and vertical clearance at underpasses. (8 mark)
UNIT 3 - DESIGN OF FLEXIBLE AND RIGID PAVEMENTS
135
1. Design factors. (8mark)(University repeated questions)
2. Design of flexible pavement. (8mark)(University repeated questions)
3. Design of rigid pavement. (8mark)(University repeated questions)
4. ESWL (Equivalent single wheel load).(8mark)(University repeated questions)
5. Critical load point and problems (Interior, edge, corner problem) (8mark)
(University repeated questions)
UNIT 4 - HIGHWAY CONSTRUCTION MATERIALS AND
PRACTICE
1. Soil and tests. (8mark)
2. Aggregates and tests. (13 mark)(University repeated questions)
3. Bitumen and tests. (13 mark)(University repeated questions)
4. Abrasion test, flash and fire point test, softening test. (8mark)
(University repeated questions)
5. Construction procedure of bituminous and cement concrete. (8mark)
(University repeated questions)
6. Modern Materials (glass, fiber, Geo-Membrane, geo-textiles and plastics). 8mark)
(University repeated questions)
7. Quality control measure. (8mark)
8. Highway drainage and types. (8mark)(University repeated questions)
9. Construction machineries. (8mark)(University repeated questions)
UNIT 5 - EVALUATION AND MAINTENANCE OF PAVEMENTS
1. Failures of flexible pavements. (13mark)(University repeated questions)
2. Failures of rigid pavements. (13mark)(University repeated questions)
3. Pavement evaluation and strengthening.(8mark)(University repeated questions)
4. Benkelman beam method.(8mark)(University repeated questions)
5. Maintenance and repairs. (13mark)(University repeated questions)
136
6. Maintenance of bituminous road. (8mark)(University repeated questions)
7. Maintenance of cement concrete road.(8mark)(University repeated questions)
8. Highway project formulation.(13mark)
EN 8592 –WASTEWATER ENGINEERING
UNIT – I PLANNING AND DESIGN OF SEWERAGE SYSTEM
PART-A
1) Explain the meaning and significance of time of concentration.
(Nov/ Dec 2016) (Apr/May 2017)
Time of concentration is the period after which the entire catchment
area starts contributing to the runoff in drains.
Or
It is defined as the longest time without unreasonable delay that will be
required for a drop of water to flow from further point of drainage area.
It indicates the time of flow, time of entry, exit and the run off times.
TC=Ti + Tf
Ti –Inlet Time
Tf - Flow Time
It is used to indicate the
a) Inlet time
b) Outlet time
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c) Peak time
d) Maximum Runoff
It is used to drain the storm water drains.
2) Define Sewage.
Sewage (or domestic wastewater or municipal wastewater) is a type of
wastewater that is produced by a community of people. Sewage usually
travels from a building's plumbing either into a sewer, which will carry it
elsewhere, or into an onsite sewage facility (of which there are many kinds).
3) Name the sewage characteristics with which organic matter
concentration is expressed. Or What are the typical characteristics of
sewage from south Indian cities? (Nov/ Dec 2016) organic matter
Sewage is a complex mixture of chemicals, with many distinctive
chemical characteristics. These include high concentrations of ammonium,
nitrate, nitrogen, phosphorus, high conductivity (due to high dissolved
solids), high alkalinity, with pH typically ranging between 7 and 8
4) Show the BOD demand curve.
5) Examine the necessity of legal requirements and effluents
disposal of sewage.
The legal requirement for setting up a STP in factory. Right now
sewage is directly going to the municipal sewer line.
All the liquid waste from the toilet, bathroom, laundry and sink goes
into pipes which carry it to a septic tank. The effluent from the tank is
then disposed of through effluent disposal drains often referred to as leach or
French drains. Both of these methods of disposing of liquid waste are on-
site disposal systems.
138
6) Distinguish between dry weather flow & wet weather flow?
Dry weather flow Wet weather flow
It refers to the waste water flow in It refers to the waste water flow in
sewerage system during the period of
any weather.
sewerage system during the period of
wet weather.
It follows minimum infiltration. It follows maximum infiltration.
7) Discuss the various sources of waste water. (Apr/May 2017) (Nov/Dec
2017) (Nov/Dec 2018) (Nov/Dec 2017)
Types and sources of wastewater. Wastewater comes in three main types
namely Blackwater, Greywater and Yellow water. This is wastewater that
originates from toilet fixtures, dishwashers, and food preparation sinks.They
include poop, urine, toilet paper and wipes; body cleaning liquids, anal
cleansing water and so on.
8) Discuss how do you estimate storm run-off?
The Rational Method is a commonly used procedure for estimating the peak
surface runoffrate from an urban watershed for use in design of storm
water ...
Rational method
Qp =( K.Pc.A)/36
Qp = Peak rate of runoff in cumecs,
K = Coefficient of runoff,
A = Catchment area ,i n hectares, Pc = Critical rainfall intensity, in cm/hr.
Empirical formulae
Intensity duration curve
P= a/(T +b)
PC = P = Rain intensity in cm/hr
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T = Time i n minutes, a & b = Constants
For T varying between 5t o 20 minutes, a = 75 & b = 10,
P= 75/T+10
For T varying between 5t o 20 minutes, a = 100 & b = 20,
P= 100/T+20
For localities where rainfall is frequent P= 343/T+ 18
Kuichling‟ s formula
Storm frequency = 10 years, P= 267/T+20
Storm frequency = 15 years, P = 305/T +20
9) List out the sources of domestic sewage.
Human excreta (feces and urine) often mixed with used toilet paper or
wipes; this is known as blackwater if it is collected with flush toilets
Washing water (personal, clothes, floors, dishes, cars, etc.), also known
as greywater or sullage
Surplus manufactured liquids from domestic sources (drinks, cooking
oil, pesticides, lubricating oil, paint, cleaning liquids, etc.)
10) What is the use of manhole in sewerage system?
They are used to carry out inspection, cleaning and removing
obstruction in the sewer line.
Manhole allows joining of sewers or changing the direction of sewer or
alignment of sewer or both.
They allow the escape of considerable gases through perforated cover
and thus help in ventilation of sewage
11) List out the various sewer appurtenances.
Inlets: Inlets are the devices meant to admit storm water (or rain water)
and surface wash flowing along the roads/streets and convey the same
to storm water sewers or combined sewers.
Catch Basins or Catch Pits.
Clean-Outs.
140
Manholes.
Drop Manholes.
Lamp-Holes.
Flushing Devices.
Grease and Oil Traps.
12) Explain the necessity of wastewater characterization.
Characterization of the wastewater, which provides a wide variety of
information regarding the type and concentration of the contaminants
present, must be carried out to determine the type of contamination
concerned.
It‘s indicates the amount of heavy metals and synthesized organic
compounds generated by industrial activities.
As technological changes takes place in manufacturing. Changes also
occur in the compounds discharged and the resulting waste water
characteristics.
13) Distinguish between Self Cleaning velocity and Non-scouring
Velocity.
Self-cleansing velocity. In a drain pipe, a flow velocity that is high
enough to initiate scrubbing action.
The velocity of flow that prevents settlement of solids is known as self-
cleansing velocity.
Non-scouring Velocity The interior surface of the sewer pipe gets
scored due to the continuous abrasion caused by suspended solids
present in sewage.
The scoring is pronounced at higher velocity than what can be tolerated
by the pipe materials.
14) Differentiate between one pipe and two pipe system.
141
One-pipe systems are the simplest and easiest hydronic systems to
understand and install.
As the name implies, one-pipe systems have a single pipe to the
radiators, which serves as both a steam supply and a condensate return
line.
Two Pipe System. As the name implies, the system uses two pipes to
the building; a supply and a return.
In the heating season, the water in the pipes is heated with a boiler and
in the cooling season, it is cooled with a chiller.
15) State the advantages of egg-shaped sewer sections.
The main advantage of an egg-shaped sewer is that for small flows the
depth is greater and the velocity is somewhat higher than in a
circular sewer of equivalent capacity.
Thus egg-shaped sewers have better self-cleansing property at small
flows as compared to circular sewers.
16) List out the types of sewerage system.
Modern sewerage systems fall under two categories: domestic and
industrial sewers and storm sewers.
Sometimes a combined system provides only one network of pipes,
mains, and outfall sewers for all types of sewage and runoff.
17) Explain the pollution control board norms for effluent discharge
into streams.
The State Pollution Control Board is to lay down
the standards of treatment of sewage and trade effluents
to be discharged into any particular stream taking into account the
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minimum fair weather dilution available in that stream and the
tolerance limits of pollution permissible in the water of the streams
18) How will you save rain water at household level?
Rain barrels are simple containers, typically installed above ground
and for outdoor use. They vary in size depending on your requirements
and can be equipped with a tap and hose for easy use. Cisterns are
larger rainwater tanks, often installed below ground, intended for
storing water for general household use.
19) What is trap? State its quality requirements.
Pipes and Traps. Explanation: A trap is a device which is used to
prevent sewer gases from entering the buildings. The traps retain the
small amount of water and are located below or within a
plumbing fixture.
Quality requirements:
Inadequate Version Control
Insufficient Change Impact Analysis
Inadequate Change Process.
Building Functionality No One Uses
Unprioritized Requirements
20) When does it become necessary to provide manhole in sewerage
system?
Purposes of Manhole Manhole allow joining of sewers or changing the
direction of sewer alignment of sewer or both. They allow the escape
of considerable gases through perforated cover and thus help in
ventilation of sewage.
21) What is meant by the term population equivalent? (Nov/Dec 2019)
(May/June 2016)
143
Population equivalent or unit per capita loading, (PE), in waste-water
treatment is the number expressing the ratio of the sum of the pollution
load produced during 24 hours by industrial facilities and services to
the individual pollution load in household sewage produced by one
person in the same time.
22) What are the advantages of using a circular section for sewers?
(Apr/May 2017)
The advantages of circular sewers are: The perimeter of circular
sewer is the leastwith respect to the sewer of other shape. The inner
surface is smooth hence the flow ofsewage is uniform and there is no
chance of deposition of suspended particles. Thecircular sewers are
easy to construct.
23) Define (a) Sullage (b) MINAS (Nov/Dec 2019) (May/June 2016)
Sullage
The fresh waste water coming out from bathroom, kitchen except water
closets (latrine).
MINAS
Minimum National Standards.
24) Define BOD & COD?
BOD (Bio chemical Oxygen Demand): The amount of oxygen required
for survival of micro organism to oxides the organic substances at standard
temperature & standard time. (Apr/May 2019) (Nov/Dec 2018)
COD (Chemical Oxygen Demand):: The amount of oxygen required to
oxides the chemical present in the waste water.
25) Under What circumstances manholes are provided in sewerage
system? (Apr/May 2019)
144
They are used to carry out inspection, cleaning and removing obstruction in
the sewer line. Manhole allows joining of sewers or changing the direction
of sewer or alignment of sewer or both. They allow the escape of
considerable gases through perforated cover and thus help in ventilation
of sewage
26) What is small bore system? (Apr/May 2019) (Nov/Dec 2018)
(Nov/Dec 2016)
Simplified sewerage, also called small-bore sewerage, is a sewer system that
collects all household wastewater (blackwater and greywater) in small-
diameter pipes laid at fairly flat gradients. It has been estimated that
simplified sewerage reduces investment costs by up to 50% compared to
conventional sewerage.
27) How do you classify the sewage? (Apr/May 2018)
Sewage may be classified mainly into two types, namely, domestic and
industrial. All household wastes and human and animal excrete constitute
domestic sewage, whereas the industrial wastes constitute industrial sewage.
28) What is effluent standard? (Apr/May 2018)
Effluent standards are concentrations of pollutants expressed in terms of parts
per million for waste water discharged through outfall pipes from publicly
owned sewage treatment plants or industrial plants. Each pollutant, such as
biochemical oxygen demand from organic matter or suspended solids, has its
own individual standard.
29) State the objective of providing sewerage works. (Apr/May 2018)
The objective of municipal and industrial waste water treatment is to extract
pollutants, remove toxicants, neutralise coarse particles, kill pathogens so that
quality of discharged water is improved to reach the permissible level of
water to be discharged into water bodies or for agricultural land.
30) Mention the various pumps used to pump sewage? (Apr/May 2017)
(Nov/Dec 2017)
Positive Displacement Pumps. These pumps make use of rollers, gears,
impellers to displace fluid through the system.
Submersible Water Pumps. As the name suggests, these pumps are
entirely submerged in the liquid they are displacing.
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Water Pressure Booster Pumps.
Agitator Pumps.
Circulation pumps.
Progressive Cavity Pumps.
31) Differentiate Sewage, sullage, garbage. (Nov/Dec 2017)
A suspension of water and solid waste, transported by sewers to be
disposed of or processed is sewage.
The liquid discharges from kitchens, wash basins, toilets etc; sewage
Dry solid waste is known as garbage. Ex paper waste, wood etc.,
32) What is sewerage? (Nov/Dec 2017)
Sewerage is the infrastructure that conveys sewage or surface runoff using
sewers. It encompasses components such as receiving drains, manholes,
pumping stations, storm overflows, and screening chambers of the combined
sewer or sanitary sewer.
33) Why are sewers circular? (Nov/Dec 2018)
Sewers are generally circular in shape. The advantages ofcircular sewers are:
The perimeter of circular sewer is the least with respect to the sewer of other
shape. The inner surface is smooth hence the flow of sewage is uniform and
there is no chance of deposition of suspended particles.
34) Write any two computer application of design of sewer.
Consequently the ability to improve sewer network designs through the
use of Hydraulic optimization of a sewer network is one part of the
two-part network.
H2O MAP Sewer is a powerful, stand-alone GIS-based computer
program for use in the planning, design, analysis, and expansion of
sanitary, storm and combined sewer collection systems.
EPA SWMM model to design the sanitary sewer system.
35) What do you understand by self cleaning velocity? (Apr/May 2018)
146
Self cleansing velocity is the minimum velocity, which is required to keep the
solid particles in suspended form otherwise they will settle and result in
clogging.
UNIT – I PLANNING AND DESIGN OF SEWERAGE SYSTEM
PART-B AND PART-C
1) Explain the various physio-chemical characteristics of sewage and state
their environmental significance. (Nov/Dec 2019) (Apr/May 2019)
Or
Explain briefly different characteristics and composition of sewage.
(May/June 2016) 2) Explain the various sources of wastewater and their effects on
environment. Or
Explain the various sources of wastewater generation.
(Nov/Dec 2019) (Apr/May 2019) (Apr/May 2018)
3) Design a sewer running 0.7 times full at maximum discharge condition for
serving a town with a population of 100000 and provided with a water supply
at 200litres/capita day. Take slope as1 in 600. Manning‘s constant N=0.013,
peak factor as band sewage flow rate as 80% of water supplied. (Take peak
factor 2.25.) (Apr/May 2017) (Nov/Dec 2019)
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4) Explain various systems of sanitary plumbing and write down their main
characteristics of each system. (Apr/May 2019)
5) Explain the various factors to be considered in the design of sewerage
system. (Apr/May 2019)
6) How will you estimate storm water flow? Discuss the factors influencing
the storm water flow. (Apr/May 2018)
Or
Explain the estimation of storm runoff and the factors infiencing it.
(Apr/May 2017) 7) A combined sewer was designed to serve an area of 60 sq.km with an
average population density of 185 persons/hectare. The average rate of
sewage flow in 350L/Capita/day. The maximum flow is 50% in excess of the
average sewage flow. The rainfall equivalent of 12mm in 24h can be
considered for design all of which is contributing to surface runoff. What will
be the discharge in sewer? Find the diameter of the sewer if running full at
maximum discharge and velocity of 0.9m/s. (Apr/May 2018) (Nov/Dec
2018)(Method May/June 2016)
8) Explain the terms BOD and COD. Differentiate between first and second
stage BOD. (Apr/May 2017) (Nov/Dec 2016)
9) The BOD of a sewage incubated for one day at 30oc has been found to be
120mg/l. Identify the 5-day BOD at 20oC. Assume BOD rate constant K =
0.21 (base e) per day at 20oc and temperature correction coefficient
θ=1.056. (Apr/May 2017) (Nov/Dec 2016)
10) Design a sewer running 0.7 times full at maximum discharge condition
for serving a town with a population of 100000 and provided with a water
supply at 200litres/capita day. Take slope as1 in 600. Manning‘s constant
N=0.013, peak factor as band sewage flow rate as 80% of water supplied.
(Nov/Dec 2019)
11) Write the detail the various adverse effects of waste water, the estimation
of sanitary sewage flow and storm runoff with the different factors affecting
characteristics and composition of sewage. (Nov/Dec 2017)
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12) Name any 5 physical characteristics of waste water and explain in short
with reference to any five physical characteristics of waste water. (Nov/Dec
2018)
13) Define dry weather flow. Explain the various sources of dry weather flow
of sewage and also with factors affecting of DWF.
Or
Explain the various factors that affecting the dry weather flow. (Nov/Dec
2018) (May/June 2016) (Nov/Dec 2016) 14) The BOD of sewage incubated for one day at 30°C has been found to be
400 mg/l. Calculate the 5 day 20°C BOD. Assume K10= 0.12/day at 20°C.
(May/June 2016) 15) A city with a population of 100,000 has an area of hectares Calculate the
D.W.F and storm water flow for the sewer line for the following data:
i) Rate of Water supply = 200 LPCD ii) Average runoff coefficient for the
entire area = 0.5 iii) Time of concentration = 50 min iv) Assume 75% of
water supplied reaches the sewer. (May/June 2016)
16) i) Explain the one pipe and two pipe system of plumbing.(May/June
2016) ii) Explain with neat sketch manholes and inverted siphon. (May/June
2016) 17) Explain briefly about Effluent standards. (Nov/Dec 2016)
18) Enumerate and explain the various sewer appurtenances with neat
sketches.
19) Calculate the combined flow discharge of sewage for the given data. Area
to be served is 150 hectares. Population density is 50000. Time of entry is 5
minutes. Time of flow is 20 minutes Rate of water supply is 135 LPCD.
Impermeability factor =0.45. Assume 80% of water supplied turns into sewer
and peak factor as 1.5.
20) Discuss the choice available and the factors to be considered while
selecting pumps and pipes for sewerage system and explain.
21) Explain the factors influencing sanitary sewage flow and its estimation.
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22) Design a sanitary sewer to a population of 6000 receiving water at rate of
90 lpcd. Minimum self-cleansing velocity at design flow is 0.8m/s. Maximum
depth of flow is 0.5D. Assume other design criteria as applicable.
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UNIT-II PRIMARY TREATMENT OF SEWAGE
PART-A
1) Distinguish between unit operation & unit processes?
Unit operations are the physical operation to remove the impurities
present in the water and waste water.
Example: Screening, Grit chamber, Sedimentation.
Unit processes are the chemical and biological conversion on the status
of the impurities that they will be converted to a form that can be easily
separated.
Example: Coagulation, Activated sludge process, Aerated lagoon.
2) Quote the objectives of preliminary treatment of sewage.
The objective of preliminary treatment is the removal of coarse solids
and other large materials often found in raw wastewater.
In grit chambers, the velocity of the water through the chamber is
maintained sufficiently high, or air is used, so as to prevent the settling
of most organic solids.
3) What is meant by detritus tank?
It is a chamber for removing the large heavy suspended matter from
sewage.
4) What is meant by septic tank?
A septic tank is an underground chamber made of concrete, fiberglass,
or plastic through which domestic wastewater flows for basic
treatment. Settling and anaerobic processes reduce solids and organics,
but the treatment efficiency is only moderate. Septic tank systems are a
type of simple onsite sewage facility.
5) What are the three methods usually adopted for the disposal of septic
tank effluent?
On-site disposal systems
Effluent (wastewater) disposal system
Full sewage system
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6) What are the objectives of screen chamber? (Nov/Dec 2019)
The objective of screens is to remove large floating material and coarse
solids from wastewater.
It may consist of parallel bars, wires or grating placed across the flow
inclined at 30-60 degree.
7) Distinguish the grit chamber with Plain Sedimentation tank.
Grit chambers are long narrow tanks that are designed to slow down
the flow so that solids such as sand, coffee grounds, and eggshells will
settle out of the water. Grit causes excessive wear and tear on pumps
and other plant equipment.
Plain sedimentation is the process of removing suspended matters
from the water by keeping it quiescent in tanks, so that suspended
matter may settle down in the bottom due to force of gravity.
8) Show the Stoke‟s equation for discrete particle settling
9) Compare coagulation and Flocculation.
Coagulation: Particles that aggregate with themselves e.g. by the
influence of a change in pH.
Flocculation: Particles that aggregate by the use of polymers that
binds them together. Coagulation and flocculation are well-known
techniques within wastewater treatment.
10) State the objectives of grit removal.
Prevent excessive abrasion of mechanical equipment
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Prevent deposition of grit in pipes and channels (that eventually would
lead to clogging)
Reduce accumulation of grit in downstream units such as settling
basins and digesters.
11) Explain about grit chamber and their design criteria.
Grit Chamber and Primary Sedimentation Tank Design. Grit chambers are
basin to remove the inorganic particles to prevent damage to the pumps, and
to prevent theiraccumulation in sludge digestors. Grit chambers are of two
types: mechanically cleaned and manually cleaned.
12) How will you classify screens based on size of clear openings?
Screens are generally classified into three based on the size of their
openings in the screening element and mechanism of removal.
Coarse screens. Fine screens. Micro screens.
13) What process is involved in sedimentation?
Sedimentation is the process of allowing particles in suspension in water to
settle out of the suspension under the effect of gravity. There is a variety of
methods for applying sedimentation and include: horizontal flow, radial flow,
inclined plate, ballasted floc and floc blanket sedimentation.
14) What is meant by grey water? (Nov/Dec 2018)
Greywater or sullage is all wastewater generated in households or office
buildings from streams without fecal contamination, i.e. all streams except
for the wastewater from toilets. Sources of greywater include, sinks, showers,
baths, clothes washing machines or dish washers.
15) Define coagulant.
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In water treatment, coagulation flocculation involves the addition of
compounds that promote the clumping of fines into larger floc so that they
can be more easily separated from the water.
16) Define detention time.
Detention time is the length of time water is retained in a vessel or basin or
the period from the time the water enters a settling basin until it flows out the
other end. When calculating unit process detention times, we are calculating
the length of time it takes the water to flow through that unit process.
17) State the objectives of grey water harvesting. (Nov/Dec 2019)
(Apr/May 2019)
The benefits of greywater recycling include: Reduced use of freshwater, Less
strain on septic tanks or treatment plants, More effective purification,
Feasibility for sites unsuitable for a septic tank, Reduced use of energy and
chemicals, Groundwater recharge, Plant growth, Reclamation of
nutrients, etc.,
18) What are the objectives of primary treatment of sewage? (Nov/Dec
2019) (Apr/May 2019)
To reduce the strength of sewage to the extent 30% to 50%.
To remove settleable solids by 80% to 90%.
To reduce BOD by 30% to 35%.
To make the sewage fit for further treatment process.
19) What is meant by sludge volume index? (Apr/May 2019)
Sludge Volume Index (SVI) is used to describe the settling characteristics
of sludge in the aeration tank in Activated Sludge Process. ... It is defined as
'the volume (in mL) occupied by 1 gram of activated sludge after settling the
aerated liquid for 30 minutes'.
20) Write the significance of grey water harvesting. (Apr/May 2018)
The main significance of keeping greywater separate from toilet
wastewater is that the pathogen load is much reduced and
the greywater is therefore easier to treat and reuse.
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Most greywater is easier to treat and recycle than backwater (sewage),
because of lower levels of contaminants.
21) Why grit chamber is provided in sewage treatment process?
(Apr/May 2018)
Grit chambers are long narrow tanks that are designed to slow down
the flow so that solids such as sand, coffee grounds, and eggshells will
settle out of the water.
Grit causes excessive wear and tear on pumps and
other plant equipment.
22) Define the biological concept taking place in a septic tank. (Apr/May
2017)
A septic tank is an underwater sedimentation tank used for wastewater
treatment through the process of biological decomposition and
drainage. Septic tanks allow a safe disposal of wastewater and hence are
widely popular in areas that have a poor drainage system or are off the
mains sewage network
23) Why constant velocities have to maintain in a grit chamber?
(Apr/May 2017)
The velocity in the grit chamber is maintained in such a way that
the velocity will carry most organic particles through the chamber and
will tend to re-suspend any that settle, but will permit the settling of
heavier grit particles.
To maintain a fairly constant velocity of flow, a control section is used.
24) Define oxidation pond. (Nov/Dec 2017)
Oxidation ponds, also called lagoons or stabilizationponds, are large,
shallow ponds designed to treat wastewater through the interaction of
sunlight, bacteria, and algae. Algae grow using energy from the sun and
carbon dioxide and inorganic compounds released by bacteria in water.
25) Define Sludge. (Nov/Dec 2017)
155
Sludge is a semi-solid slurry that can be produced from a range of industrial
processes, from water treatment, wastewater treatment or on-site sanitation
systems. Thick, soft, wet mud or a similar viscous mixture of liquid and solid
components, especially the product of an industrial or refining process.
26) What is onsite sanitation? (Nov/Dec 2018) (Nov/Dec 2016)
Onsite sanitation (or on-site sanitation) is defined as "a sanitation system in
which excreta and wastewater are collected and stored or treated on the plot
where they are generated"
Examples are pit latrines (no treatment) and septic tanks (primary treatment
of wastewater).
27) Mention the methods of onsite sanitation.(May/June 2016)
Pit latrines (no treatment) and septic tanks (primary treatment of wastewater).
On-site sanitation systems are often connected to fecal sludge management
systems where the fecal sludge that is generated onsite is treated at an offsite
location.
28) Differentiate between BOD and COD. (May/June 2016)
. BOD (Bio chemical Oxygen Demand): The amount of oxygen
required for survival of micro organism to oxides the organic substances at
standard temperature & standard time.
COD (Chemical Oxygen Demand):: The amount of oxygen required to
oxides the chemical present in the waste water.
29) Define hydraulic subsidence value?
Land subsidence is a gradual settling or sudden sinking of the Earth's surface.
Subsidence - sinking of the ground because of underground material
movement—is most often caused by the removal of water, oil, natural gas, or
mineral resources out of the ground by pumping, fracking, or mining
activities.
30) What is oxidation ditches?
An oxidation ditch is a modified activated sludge biological treatment process
that utilizes long solids retention times (SRTs) to remove biodegradable
organics. Oxidation ditches are typically complete mix systems, but they can
be modified to approach plug flow conditions.
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UNIT-II PRIMARY TREATMENT OF SEWAGE
PART-B AND PART-C
1) Explain with neat sketch component parts, functioning advantages and
disadvantages of septic tank. Also discuss various methods of disposal of
septic tank effluent. (Nov/Dec 2019) (Apr/May 2018) (Nov/Dec 2017)
(Nov/Dec 2018) (May /June 2016)
Or
Explain the function of septic tank with a neat sketch. Also discuss the design
criteria. (Apr/May 2019)
2) Assuming suitable criteria design a screen chamber with 20mm spacing of
bar for a proposed STP expected to treat 30ML/d maximum fow.Draw a neat
sketch of the unit .(Apr/May 2019)
3) Explain briefly the operation and maintenance of sewage treatment plants.
(Nov/Dec 2019) (Nov/Dec 2016)
4) Design a primary clarifier of full scale STP with ASP for an average
sewage flow of 12Mld.Assume suitable data if necessary. (Nov/Dec 2019)
(Nov/Dec 2016)
5) Discuss in detail about classification of screens and state application of
each class. (Apr/May 2018)
6) Show the design a septic tank with dispersion pit for a hostel with a
population of 150 and peak discharge of 205 Lit Per Min Take desludging
period as one year. Assume suitable design criteria and draw a neat sketch of
the designed tank. (Apr/May 2017)
7) i) Explain the velocity control devices in Grit Channel. (Apr/May 2017)
ii) Discuss in brief various types of settling in sedimentation tank.
(Apr/May 2017)
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8) i) with the help of neat sketch explain the process of primary treatment of
sewage. (Nov/Dec 2017)
ii) What is grey water harvesting and how it being carried out? (Nov/Dec
2017)
9) What do you mean by primary treatment for sewage treatment and write a
short note on bar screens, grid chamber and primary sedimentation tanks.
(Nov/Dec 2018)
10) Design a Grit chamber for an average sewage flow of 14 Mld.Diameter of
incoming sewer is 500mm.Assume suitable data if required. (May /June
2016)
11) What is meant by sedimentation tank and explain its types with neat
sketch.
12) Show the design a circular primary sedimentation tank to treat an average
sewage flow of 5000 m3/day, suitably assuming the design criteria. Draw a
neat sketch of the designed tank.
13) Examine and design a septic tank for the following data:-
i) No of persons = 140
ii) Sewage contribution = 120 LPCD
iii) Desludging period = 1 year
iv) Length : Breadth ratio = 1 :2.5
v) Design a dispersion trench adopting infiltration rate as1200 lit/m2day.
14) Design a primary settling tank unit for a peak flow of 40 MLD in a
sewage treatment plant.
15) Explain in detail about the on-site sanitation and its methods.
16) Write the design criteria for a grit chamber and brief its construction and
functioning and describe the working of grit chamber and its types.
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UNIT III - SECONDARY TREATMENT OF SEWAGE
PART-A
1) List the objectives of Secondary and Tertiary treatment of sewage.
Secondary treatment is biological conversion of dissolved and colloidal
organics into biomass that can be subsequently removed by sedimentation
while tertiary treatment is the removal of suspended solids and nutrients such
as nitrogen and phosphorus.
2) Define sludge solids retention time in ASP design.
The Solids Retention Time (SRT) is the average time the activated-sludge
solids are in the system. The SRT is an important design and operating
parameter for the activated-sludge process and is usually expressed in days.
3) Identify the modified forms of conventional ASP.
In conventional ASP many modifications can be made both with respect to
basin configuration, asrespect to basin configuration, as well as aeration
techniques.
4) What is the function of aeration in Activated Sludge Process?
Aeration in an activated sludge process is based on pumping air into a tank,
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which promotes the microbial growth in the wastewater. The microbes feed
on the organic material, forming flocks which can easily settle out.
5) When will you prefer anaerobic treatment of sewage over an aerobic
process?
Aerobic treatment is typically applied to efficiently treat low
strength wastewater (COD <1000 mg/L) when the treatment requires the
presence of oxygen. Whereas, anaerobic treatment is typically applied to treat
wastewater with higher organic loading (COD >4000 mg/L).
6) What is meant by sludge volume index? (Apr/May 2019)
Sludge Volume Index (SVI) is used to describe the settling characteristics
of sludge in the aeration tank in Activated Sludge Process. ... It is defined as
'the volume (in mL) occupied by 1 gram of activated sludge after settling the
aerated liquid for 30 minutes'.
7) Discuss the term re-circulation ratio in trickling filter.
Recirculation ratios are expressed as the volume of return recirculation flows
to the volume of the influent wastewater. Recirculation ratios generally run
from 0.5:1 to 4:1. To determine if enough sludge is being removed from a
clarifier various types of sludge depth finders are used.
8) Distinguish between suspended growth processes and attached growth
processes with suitable examples
Suspended growth processes
Wastewater treatment processes in which the microorganisms and bacteria
treating the wastes are suspended in the wastewater being treated. The wastes
flow around and through the suspended growths. The various modes of the
activated sludge process make use of suspended growth reactors.
Attached growth processes
Attached-growth processes (also known as fixed-film processes) are
biological wastewater treatment processes with the biomass attached to some
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type of media. The media normally found at wastewater treatment plants are
rock, ceramic, plastic materials, and slag.
9) Illustrate how advanced treatment of sewage is different from
conventional treatment system.
Tertiary and/or advanced treatment. However, advanced treatment processes
are sometimes combined with primary or secondary treatment (e.g., chemical
addition to primary clarifiers or aeration basins to remove phosphorus) or
used in place of secondary treatment (e.g., overland flow treatment of
primary effluent).
10) Classify trickling filter and state its types?
TYPES OF TRICKLING FILTERS. The Trickling filters are classified based
on hydraulic or organic loading, as low rate trickling filter (LRTF), high
rate trickling filter (HRTF) and Roughing Filter.
11) Examine hydraulic loading rate of a trickling filter?
The hydraulic loading rate is the total flow including recirculation appied on
unit area of the filter in a day, while the organic loading rate is the 5 day
20°C BOD, excluding the BOD of the recirculant, applied per unit volume in
a day. Recirculation is generally not adopted in low rate filters.
12) State the advantages of UASB reactor.
Anaerobic pre-treatment of domestic sewage using UASB reactor systems
offers a number of advantages, e.g. system compactness, negligible or no
energy consumption, stabilised excess sludge production, potential for energy
recovery, low-cost accessibility of sewage for agricultural reuse purposes,
etc.
13) Compare the oxidation ditch with oxidation pond.(May/June 2016)
An oxidation ditch is a large circular basin equipped with aerators that i s
used to remove organic matter and pollutants from sewage through the
processes of adsorption, oxidation, and decomposition. Ensures stable,
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continuous dissolved oxygen measurement. Reduces operating costs.
(Apr/May 2019) (Nov/Dec 2018)
Oxidation ponds, also called lagoons or stabilization ponds, are large,
shallow ponds designed to treat wastewater through the interaction of
sunlight, bacteria, and algae. Algae grow using energy from the sun and
carbon dioxide and inorganic compounds released by bacteria in water.
14) What is the difference between reclamation and reuse of sewage.
Reclamation
Reclaimed or recycled water is the process of converting wastewater into
water that can be reused for other purposes. Reuse may include irrigation of
gardens and agricultural fields or replenishing surface water and
groundwater.
Reuse of sewage.
It is the process of the wastewater that flows down the drain – yes, including
toilet flushes – is now being filtered and treated until it's as pure as
spring water, if not more so. It might not sound appealing, but recycled
water is safe and tastes like any other drinking water, bottled or tap.
15) Distinguish between HRT and SRT.
HRT They are also known as standard rate or conventional rate filters. The
settled sewage is applied to the filter bed and after trickling through it, passes
through the final sedimentation tank for removal of most of the stabilized
solids.
SRT Low Rate Filters. They are also known as standard rate or
conventional rate filters. The settled sewage is applied to the filter bed and
after trickling through it, passes through the final sedimentation tank for
removal of most of the stabilized solids.
16) What is meant by MLVSS?
MLVSS - Mixed liquor volatile suspended solids. MVLSS is generally
defined as the microbiological suspension in the aeration tank of an activated-
sludge biological wastewater treatment plant.
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17) Differentiate between aerobic pond and anaerobic pond.
Anaerobic and facultative ponds are designed for BOD removal,
while aerobic ponds are designed for pathogen removal (see also pathogens
and contaminants). Facultative ponds should be constructed to a depth of 1 to
2.5 m and have a detention time between 5 to 30 days. Aerobic ponds are
usually between 0.5 to 1.5 m deep
18) Summarize about sludge recycling.
Groundbreaking sewage sludge recycling with EEW Energy from Waste. At
the same time the sludge also contains the resource phosphorus. This nutrient
essential for us all encourages plant growth, which is one of the reasons
why sludge has for years been used as an agricultural fertilizer.
19) Explain how do you determine organic loading rate of a trickling
filter? (Apr/May 2019)
The hydraulic loading rate is the total flow including recirculation appied on
unit area of the filter in a day, while the organic loading rate is the 5 day
20°C BOD, excluding the BOD of the recirculant, applied per unit volume in
a day. Recirculation is generally not adopted in low rate filters.
20) Compare activated sludge process and trickling filter process of
sewage treatment. (Apr/May 2017)
In the activated sludge system, the wastewater is brought into contact with a
diverse group of micro-organisms in the form of a flocculent suspension in an
aerated tank, whereas in the biological film system, also known as trickling
filters, the wastewater is brought into contact with a mixed microbial
population in the form of a film of slime attached to the surface of a solid
support system.
21) Write the formula for recirculation factor.
Recirculation Factor:
= (1+ Recirculation Ratio). If the sewage has high concentration of B.O.D., it
can be treated by passing number of times through the trickling filters and
settling tanks.
22) List out the types of high rate filters.
Types of trickling filters
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Low Rate Trickling Filter (LRTF)
High Rate Trickling Filter (HRTF)
Roughing Filter
Two-Stage Trickling Filters
23) Write down the components of UASB reactor.
Critical elements for the design of UASB reactors are the influent distribution
system, the gas-solids separator, and the effluent withdrawal design. The gas
that rises to the top is collected in a gas collection dome and can be used as
energy (see also use of biogas).
24) What is the role of stabilization ponds in secondary treatment of
sewage?
Waste stabilization ponds (WSPs or stabilization ponds or waste stabilization
lagoons) are ponds designed and built for wastewater treatment to reduce the
organic content and remove pathogens from wastewater. They are man-made
depressions confined by earthen structures.
25) What is the principle of UASB? Or Write short note no UASB.
(Apr/May 2019) (Apr/May 2018) (Nov/Dec 2018) (May/June 2016)
UASB uses an anaerobic process whilst forming a blanket of granular sludge
which suspends in the tank. Wastewater flows upwards through the blanket
and is processed (degraded) by the anaerobic microorganisms. The upward
flow combined with the settling action of gravity suspends the blanket with
the aid of flocculants.
26) Define the term activated sludge. (Apr/May 2018)
Activated sludge is a thick soft substance used for removing pollutants from
waste water by a biological reaction that involves oxygen. The activated
sludge is then separated from the treated wastewater and disposed of or
returned to the process as needed.
27) What is the significance of solids retention time in ASP design?
Solids Retention Time (SRT) is a critical activated sludge design and
operating parameter. The traditional method for controlling SRT is to
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manually adjust the sludge wasting rate based on the food-to-microorganism
(F/M) ratio or mixed liquor suspended solids (MLSS) concentration.
28) Define F/M ratio.
The term Food to Microorganism Ratio (F/M) is actually a measurement of
the amount of incoming food (Lbs of Influent CBOD) divided by the Lbs
of Microorganisms in your system.
29) Define Sequencing Batch Reactor.
Sequencing batch reactors (SBR) or sequential batch reactors are a type of
activated sludge process for the treatment of wastewater. SBR reactors treat
wastewater such as sewage or output from anaerobic digesters or mechanical
biological treatment facilities in batches.
30) Define Membrane Bioreactor.
Membrane bioreactor (MBR) is the combination of a membrane process like
microfiltration or ultra filtration with a biological wastewater treatment
process, the activated sludge process. It is now widely used for municipal and
industrial wastewater treatment.
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UNIT III - SECONDARY TREATMENT OF SEWAGE
PART-B AND PART-C
1) Estimate the size of a high rate trickling filter for the following data:
Sewage flow= 6 MLD; Recirculation ratio= 1.5; BOD of Raw sewage = 230
mg/l; BOD removal in PST = 30%; BOD of treated effluent required= 20
mg/l. (Nov/Dec 2019) (Method Apr/May 2019) (Method Apr/May 2017)
(May/June 2016) (Nov/Dec 2016)
2) i) Explain the Reclamation and Reuse of sewage. (Nov/Dec 2019)
(May/June 2016)
Or
Write the process of reclamation and reuse of sewage. With the help of neat
sketch explain the sewage recycle plant for a residential complex. (Nov/Dec
2017) ii) Discuss in detail about waste stabilization pond. (Nov/Dec 2019)
(May/June 2016)
Or
166
Elucidate the waste stabilization pond system of sewage treatment.
(Apr/May 2018)
3) Draw the typical process flow diagram for a UASB reactor and explain the
working principle. (Apr/May 2019)
4) Elaborate the principle, construction and design aspects of trickling filter
with neat sketch. (Apr/May 2018)
5) Explain the basic operation of an activated sludge process with a flow
diagram. Also mention its operating troubles with remedial suggestions.
(Apr/May 2017) (Nov/Dec 2017) (Nov/Dec 2016)
6) Examine and design a single stage trickling filter to yield an effluent
BOD5 of 30 mg/l. The influent BOD following primary clarification is 175
mg/l and the flow is 15000 m3/d. Maintain a hydraulic loading rate of 20
m3/m2/d and a filter depth of 2 m. Assume a recirculation ratio of 1.5.
7) Design an oxidation ditch for a community of 7500 with per capita sewage
contribution of 90 Lpcd and BOD 250 mg/l, the desired BOD of the treated
sewage is 30mg/l.
8) Explain about Sequencing Batch Reactor and Membrane Bioreactor.
UNIT IV - DISPOSAL OF SEWAGE
PART-A
1) Describe the methods of disposal of sewage by land treatment.
Such a technology incorporates waste-water treatment, water reuse, crop
utilization of nutrients and waste-water disposal. It involves the application
of wastewater to vegetated land by means of various techniques, including
sprinkling methods or surface techniques such as graded-border and furrow
irrigation.
2) Define sewage sickness.
When sewage is continuously applied on a piece of land the pores or void in
the soil gets clogged and the free circulation of air will be prevented .This is
known as sewage sickness.
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3) What is meant by self-purification of rivers?
Running water is capable of purifying itself with distances through a process
known as self- purification. This is the ability of rivers to purify itself of
sewage or other wastes naturally. It is produced by certain processes which
work as rivers move downstream.
4) What are the different zones of pollution?
There are 4 types of pollution zones in the river, namely zone of
degradation, zone of active decomposition, zone of recovery and zone of
clear water.
5) What is meant by disposal by dilution?
Disposal by dilution is the simple method of discharging wastewater into a
surface water such as a river, lake, ocean, estuaries or wetlands. ... The degree
of pollution depends on the dilution, volume and composition of the
wastewater as compared to the volume and quality of the water with which it
is mixed
6) Define dilution factor.
A dilution factor (DF) is the ratio of concentration in the effluent to
concentration in the receiving water after mixing in the receiving wate
7) List out the various natural forces of purification.
Dilution: When sewage is discharged into a large volume of water
flowing in a natural stream or river, it is dispersed and dilution takes
place.
Oxidation: ADVERTISEMENTS.
Reduction.
Sedimentation.
Action of Sunlight.
8) Draw the oxygen deficit curve.
The amount of resultant oxygen deficit can be obtained by algebraically
adding the deoxygenation and reoxygenation curve. The resultant curve is
known as oxygen sag.
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9) What are the methods of applying sewage effluents to farms?
In small sewage treatment plants, sludge is processed in a variety
of ways including: aerobic digestion, storage in sludge lagoons,
direct application to sludge drying beds, in-process storage (as in
stabilization ponds), and land application.
10) Examine the difference between effluent irrigation and sewage
farming.
Effluent is a more of a directional word when applied to wastewater or
sewage. Sewage leaving my home is an effluent. When it enters the local
treatment system it is an influent. Once treated and leaving the treatment
facility, it is again an effluent.
All sewage is wastewater but not all wastewater is sewage. Water that has
been used for its purposes is a wastewater. In a home, it may be grey
water or sewage. In an industry, wastewater may be water contaminated
with oils, acids, alkalis, etc.
11) List out any 5 standards for discharge of sewage in surface water
source.
Standards
pH -- 5.5 to 9.0
Chemical Oxygen Demand (COD) -- 250 mg/l
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Total Suspended Solids (TSS) -- 100 mg/l -- 200 mg/l (Land
for irrigation)
Oil & Grease (O & G) -- 10 mg/l
NoiseLevel: Leq 75 dB(A) Leq 70 dB(A)
12) What do you mean by zone of recovery?
The zone of recovery is the third zone of pollution in the river where river
tries to recover the polluted water through the self purification process. ...
Explanation: The water retains its original dissolved oxygen concentration
in the zone of clean water.
13) Write down the streeter-phelps equation.
The Streeter–Phelps equation is used in the study of water pollution as a
water quality modelling tool. The model describes how dissolved oxygen
(DO) decreases in a river or stream along a certain distance by
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degradation of biochemical oxygen demand (BOD)
14) Under what condition, the effluent irrigation method for
disposal of sewage can be favourably adopted?
The Dilution method for disposing of the sewage can
favorable by adoptedunder the following conditions: When the
industrial waste water are disposed of in to public sewers, their and has to
be adopted. The method of effluent irrigation will prove useful in areas of
low.
15) Enlist the preventive measures for sewage sickness.
Preventive measures The land is unable to receive the excess sewage in a
satisfactory way and it ultimately clogs up. Depth of sewage on land should
be carefully decided by keeping in view the
climaticonditions, drainage facilities, nature of crops and characteristics of
soil.
16) Define Mass balance Principle.
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The mass Balance principle states that all matter (which is mass) is not
created nor destroyed, it remain constant. Given this, we can state that all
inlet, outlets, production and consumption of species for a given moment are
the concept named "accumulation" of the system.
17) Why land disposal method is generally found to be a better choice
in hot climatic areas?
Incineration used to be the method of choice for most hazardous health-
atmosphere. Land disposal may result in groundwater pollution if the landfill
and process is usually selected to treat wastes that cannot be recycled.
cold climates, steam and/or hot water from incinerators can be used to
Such areas have good road.
18) What are the factors influencing the rate at which oxygen is
supplied by the atmosphere to the polluted water?
Dissolved oxygen concentrations are constantly affected by diffusion and
aeration, photosynthesis, respiration and decomposition.
While water equilibrates toward 100% air saturation, dissolved oxygen levels
will also fluctuate with temperature, salinity and pressure changes
19) Define SAR.
The index used is the Sodium Adsorption Ratio (SAR) that expresses the
relative activity of sodium ions in the exchange reactions with the soil. This
ration measures the relative concentration of sodium to calcium and
Magnesium
20) Enlist sodium hazards in sewage farming.
Irrigation with treated wastewater causes land salinity, also causes land
sealing and sodium accumulation, which could cause increased run off and
land erosion. One particular concern of the environmental problems is long-
term sustainability issue (e.g. the increase of salinity and sodium content in
soil).
21) What do you mean by soil dispersion system?
Dispersion is a process that occurs in soils that are particularly vulnerable to
erosion by water. In soil layers where clays are saturated with sodium ions
("sodic soils"), soil can break down very easily into fine particles and wash
away.
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22) How sewage disposal affects public health? Improper disposal of waste can greatly affect the health of the population
living nearby the polluted area or landfills. Exposure to improperly
handled wastes can cause skin irritations, blood infections, respiratory
problems, growth problems, and even reproductive issues.
23) What do you understand by dilution and under what circumstances
it is most suitable?
Dilution is the process of reducing the concentration of a solute in solution,
usually simply by mixing with more solvent. Example 1: You can add water
to concentrated orange juice to dilute it until it reaches a concentration that is
pleasant to drink.
24) Define sewage farming.
Sewage farming allows use for irrigation of water which might otherwise be
wasted. Some of the nutrients and organic solids in wastewater can be
usefully incorporated into soil and agricultural products rather than fouling
natural aquatic environments.
25) What is meant by land treatment in sewage disposal?
Land Treatment. Land treatment is defined as the controlled application
of waste water onto the land surface to achieve a specified level
of treatment through natural physical, chemical, and biological processes
within the plant soil-water matrix. Waste water is a recyclable commodity.
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UNI IV - DISPOSAL OF SEWAGE
PART-B AND PART-C
1) A large stream has a rate of re-aeration constant, Kr = 0.24 per day (to
base 10) and de-oxygenation constant, Kd = 0.1 per day (to the base
10).The initial deficit of the mixture of stream and waste water at the
point of reference Do = 4 mg/l and the ultimate 5 day BOD, Lo =
35mg/l. Find the D.O deficit and critical time.
2) Name the various actions involved in the self-purification process of a
stream and explain them briefly.
3) In Indian towns and cities, the land disposal method is mostly
preferred. Why?
4) Draw a typical oxygen sag curve and explain its meaning and state its
importance.
5) Determine the BOD of river water at the discharge point of the treated
sewage from a town having a BOD of 30mg/l discharged at the rate of 5
m3/s into a river having a flow of30m3/s and no BOD.
6) Explain the various zones of pollution in river stream.
7) Explain briefly about the methods of sewage disposal.
8) What is sewage farming? What are its advantages over the method of
disposal of sewage by dilution?
9) Discuss briefly about the disposal of sewage in sea water.
10) Justify under which conditions, the effluent irrigation method for
disposal of sewage can be adopted.
11) Write short notes on soil dispersion system.
12) How will you apply sewage effluents to farms and explain their
methods in detail.
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13) What is meant by sewage sickness and list out the preventive
measure to control it?
14) Which method of sewage disposal is safe and best? Justify your
answer.
15) A waste water treatment plant produces sludge of 1000kg dry solids
per day with a moisture content of 97%. The solids are 65% volatile
with specific gravity 1.05 and inorganic solids of specific gravity
2.55. Determine the sludge volume of raw sludge, after dewatering to
70% and after incineration.
16) Derive Streeter Phelps Equation.
17) What are the environmental and health risks associated with sewage
farming?
18) Summarise the principle of the self-purification process of river and
the various stages of oxygen sag curve and explain the salient
features.(Apr/May 2019)
19) Explain the factors affecting the self purification of surface waters.
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UNIT V - SLUDGE TREATMENT AND DISPOSAL
PART-A
1) List the different unit processes involved in sludge treatment.
Plant unit processes include coarse screening, influent pumping, fine
screening, grit removal, primary clarification, air
activated sludge incorporating biological nutrient removal, and chlorination.
2) What is the difference between raw sludge and secondary
sludge?
Primary sludge is generated from chemical precipitation, sedimentation, and
other primary processes, whereas secondary sludge is the activated waste
biomass resulting from biological treatments. Some sewage plants also
receive septage or septic tank solids from household on-site wastewater
treatment systems
3) Why sludge treatment is necessary?
Treatment and disposal of sewage sludge are major factors in the design and
operation of all wastewater treatment plants. Two basic goals of
treating sludge before final disposal are to reduce its volume and to stabilize
the organic materials. Smaller sludge volume reduces the costs of pumping
and storage.
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4) Summarize the objectives of sludge thickening and its method. Sludge thickening and dewatering. Thickening is the first step of sludge
treatment. It aims to separate the solid and liquid phases of the sludge. Then,
dewatring process reduces the water content of the sludge.
5) What is meant by acid production and acid regression.
Acid regression stage.
A stage of anaerobic digestion during which the production of
volatile acids is reduced and acetate and ammonia compounds form, causing
the pH to increase.
Acid production stage
The first stage involves liquefying of solid material in the sludge. This
process is called hydrolysis. The second stage is rapid and involves digestion
of the soluble solids that resulted from the previous stage. This process is
carried out at molecular level by acid (primarily acetic, propionic and
butyric acid etc.)
6) Enlist the factors affecting sludge digestion.
Some parameters affecting the aerobic digestion process are: (1) rate
of sludge oxidation, (2) sludge temperature, (3) system oxygen requirements,
(4) sludge loading rate, (5) sludge age, and (6) sludge solids characteristics.
7) Define sludge seeding.
Sludge Bacterial Seeding for Biological System
Usually there are two approaches involved, one is the dry seeding using
prepared bacteria cultures in powder form (also called bioaugmentation) and
another is the wet seeding meaning that the sludge is obtained from an
existing wastewater treatment plant.
8) Distinguish between mesophilic digestion and thermophilic
digestion.
Thermophilic anaerobic digestion showed higher organic matter degradation
(especially fiber), higher pH and higher methane (CH4) yield, as well as
better percentage of ultimate CH4 yield retrieved and lower residual
CH4 emission, when compared with mesophilic conditions. In addition,
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lower microbial diversity was found in the thermophilic reactors, especially
for Bacteria, where a clear intensification towards Clostridia class members
was evident.
9) Define sludge conditioning. (Apr/May 2019) (Apr/May 2017) (Nov/Dec
2017) (Nov/Dec 2016)
Sludge conditioning is a process whereby sludge solids are treated with
chemicals or various other means to prepare the sludge for dewatering
processes, in other words, to improve dewatering characteristics of
the sludge.
10) What are the factors to be considered while designing sludge
digestion tank.
Some parameters affecting the aerobic digestion process are: (1) rate of
sludge oxidation, (2) sludge temperature, (3) system oxygen requirements, (4)
sludge loading rate, (5) sludge age, and (6) sludge solids characteristics.
11) Discuss the objectives of treatment of sludge.
There are four main treatment objectives: (1) pathogen inactivation, (2)
dewatering, (3) stabilization, and (4) nutrient management. 1. Pathogen
inactivation: A key objective of fecal sludge treatment is often pathogen
reduction to protect public health.Fecal sludge treatment inactivates
pathogens in various ways.
12) What are the steps involved in sludge treatment?
Step 1 – Sludge Thickening. The first step in the sewage sludge
treatment plan is called thickening.
Step 2 – Sludge Digestion. After amassing all the solids from the
sewage sludge begins the sludge digestion process.
Step 3 – Dewatering.
Step 4 – Disposal.
13) What is meant by ripened sludge? (Nov/Dec 2016)
The ripened sludge is nothing but the digested sludge is collected at the
bottom of the digestion tank and it is alkaline in nature.
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14) Examine the need for sludge digestion?
Sludge digestion is a biological process in which organic solids are
decomposed into stable substances. Digestion reduces the total mass of
solids, destroys pathogens, and makes it easier to dewater or dry
the sludge. Digested sludge is inoffensive, having the appearance and
characteristics of sewage.
15) Examine the various methods of sludge dewatering.
In the simplest terms, dewatering is the removal of liquids from
a sludge slurry. The process involves using one of three dewatering
techniques. The three techniques are plate and frame filter press, centrifuge
and belt press.
16) List out the common methods of sludge disposal.
The most common treatment options include anaerobic digestion, aerobic
digestion, and composting. Sludge digestion offers significant cost
advantages by reducing sludge quantity by nearly 50% and providing biogas
as a valuable energy source.
17) Examine how does one improve the dewatering ability of sludge?
To improve sludge dewatering, primarily chemical processes are applied, but
also thermal and freeze-thaw methods. By using these methods, sludge is
prepared to separate water in for example, belt presses or centrifuges.
18) What are the different equipments used in sludge thickening?
The centrifuge types which have been used for sewage sludge
dewatering include the solid bowl, basket and disc centrifuges. The most
frequently used is the continuous countercurrent solid bowl centrifuge.
19) List out the processes involved in anaerobic sludge digestion.
The four key stages of anaerobic digestion involve hydrolysis, acidogenesis,
acetogenesis and methanogenesis. The overall process can be described by
the chemical reaction, where organic material such as glucose is
biochemically digested into carbon dioxide (CO2) and methane (CH4) by
the anaerobic microorganisms.
20) Sketch the effect of temperature on the digestion period.
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The effect of temperature on digestive and assimilation efficiency, gut
passage time and appetite in an ambush foraging lizard, Cordylus melanotus
melanotus. In ectotherms, an increase in body temperature increases
metabolic rate and may increase rates of digestive processes.
21) What is meant by multistage digestion.
For solids content, low will handle up to 15% solid content. Above this level
is considered high solids content and can also be known as
dry digestion.A multistage process utilizes two or more reactors
for digestion to separate the methanogenesis and hydrolysis phases.
22) Define supernatant liquor.
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The liquid above settled solids, as in a gravity separator. The usually
clear liquid overlying material deposited by settling, precipitation, or
centrifugation.
23) What are the methods of sludge conditioning? (Nov/Dec 2019)
(Apr/May 2017)
Method of sludge conditioning
Chemical Conditioning
Thermal Conditioning
Freeze-Thaw Conditioning
24) What are the objectives of sludge dewatering? (Nov/Dec 2019)
The purpose of sludge dewatering is for waste minimization and to achieve
overall cost efficiency for disposal. Sludge dewatering is typically focused on
reducing the weight and volume of the sludge so that disposal costs -
including transportation - are kept to a minimum.
25) How do you remediate sewage sickness? (Apr/May 2019)
The primary goal of remediation must be the complete removal and disposal
of water and contamination using the sanitary sewer system if possible. Wet
extraction systems should be used to completely remove sewage and water
used for cleaning.
26) Enlist methods of treated sewage effluent disposal. (Apr/May 2018)
Municipality Systems. Municipal sewage systems
have treatment plants connected to them.
Off-site Sewer Systems. These systems came as a result of increased
urbanization.
On-site Systems.
Full Sewage Systems.
Lagoons.
Pit Latrines.
27) Give out the the advantages of sludge conditioning. (Apr/May 2018)
Thermal conditioning of wastewater sludge has the following advantages:
Except for straight waste activated sludge, the process will
produce sludge with good dewatering characteristics. Cake solids
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concentrations of 50 to 60% are typically obtained with
mechanical dewatering equipment following thermal conditioning.
28) What is meant by sludge dewatering?
Sludge Dewatering. Sludge dewatering is the separation of a liquid and solid
phase whereby, generally, the least possible residual moisture is required in
the solid phase and the lowest possible solid particle residues are required in
the separated liquid phase.
Dewatering (Apr/May 2017)
The removal of water from solid material or soil by wet classification,
centrifugation, filtration, or similar solid-liquid separation processes, such as
removal of residual liquid from a filter cake by a filter press as part of various
industrial processes.
29) What is sludge thickening? (Nov/Dec 2017)
Sludge thickening is a process in which the solids concentration is increased
and the total sludge volume is correspondingly decreased, but the sludge still
behaves like a liquid instead of a solid. The advantages of sludge
thickening in reducing the volume of sludge to be handled are substantial.
30) What are the disadvantages of land disposal of wastes? (Nov/Dec
2018)
Health-hazard - insects, rodents etc.
Damage due to air pollution.
Ground water and run-off pollution.
31) Define sludge density index.(May/June 2016)
Sludge density index (SDI) A calculation used to indicate the settleability
of sludge in a secondary clarifier or effluent that is related to the calculation
for sludge volume index (SVI). The weight in grams of 100 milliliters
of sludge after settling for 30 minutes. SDI = 100/SVI.
32) Name the methods of disposal of sewage by land treatament.
(May/June 2016)
Land treatment is the controlled application of waste-water to the land at rates
compatible with the natural physical, chemical and biological processes that
occur on and in the soil. The three main types of land treatment systems used
are slow rate (SR), overflow (OF), and rapid infiltration (RI) systems.
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33) What is sludge drying beds.
Sludge-drying beds provide the simplest method of dewatering. A
digested sludge slurry is spread on an open bed of sand and allowed to
remain until dry. Drying takes place by a combination of evaporation and
gravity drainage through the sand.
UNIT V - SLUDGE TREATMENT AND DISPOSAL
PART-B AND PART-C
1) Explain sludge dewatering with the different methods of sludge
dewatering. (Nov/Dec 2019)
2)i) Explain about sludge disposal methods. (Nov/Dec 2019)
ii) Discuss about the Bio-gas treatment and its advantages. (Nov/Dec 2019)
3)Draw a neat sketch of a high rate two-stage anaerobic sludge digester and
explain its working principle.(Apr/May 2019) (Nov/Dec 2016)
4) With the help of a diagram, explain the working of a standard rate sludge
digester? (Apr/May 2017)
5)Explain the characteristics of sludge and how biogas can be removed.
(Nov/Dec 2017)
6) Explain the various advances in the treatment of sludge and mode of
disposal. (Nov/Dec 2017)
7) What do you mean by sludge thickening process? Explain gravity
thickening and air floatation unit with a neat sketch. (Nov/Dec 2018)
8) Explain about Bio gas recovery? (Nov/Dec 2016)
10) Explain in detail about the factors affecting sludge digestion.
11) Design a sludge digestion tank with the following data.
i) Average flow of sewage = 60 MLD
ii) Total Suspended Solids in raw sewage = 350 mg/L
iii) Volatile Suspended solids = 250 mg/L
iv) Moisture content of the digested sludge = 87%
Assume 65% of removal in done in primary setting tank and fresh sludge has
water content of 95%.
12) Describe briefly about the sludge digestion tank with a neat sketch.
13) Discuss about the recent advances in sludge treatment.
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14) Secondary sedimentation tank of a waste water treatment plant produces
1100kg (dry basis) solids with moisture content of95%.Solids are of 70%
volatile with specific gravity of 1.05 and 30% being fixed with specific
gravity of 2.6. Determine the sludge volume as it is produced and after the
incineration.
15) A waste water treatment plant produces sludge of 1000 kg dry solids per
day with a moisture content of 97%. The solids are65% volatile with specific
gravity 1.05 and inorganic solids of specific gravity 2.55. Determine the
sludge volume of raw sludge, after dewatering to 70% and after incineration.
16) Design sludge drying beds to dewater the digested sludge produced
from wastewater treatment plant based on Activated Sludge Process
designed for5000 population. Assume dry solid concentration and dry
solid loading rate as 70 g/capita/day and 100 kg/m2/day. Take 7% solid
content in digested sludge and specific gravity of digested sludge as 1.02
17) Design a sludge digestion tank for 40,000 people. The sludge content per
capita per day is 0.068 kg. The moisture of the sludge is 94%. The Specific
Gravity of the wet sludge is 1.02 and 3.5 percent of the digester volume is
daily filled with the fresh sludge, which is mixed with the digested sludge.
18) Describe briefly the heat treatment method of sludge conditioning.
19) What parameters you will consider while designing sludge digestion
tank?
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OCE551: AIR POLLUTION AND CONTROL ENGINEERING
III/VI BE CIVIL ENGINEERING
TWO MARKS QUESTIONS AND ANSWERS
UNIT I - INTRODUCTION
1. What is the structure of the Atmosphere?
The atmosphere consists of zones or layers arranged like spherical shells
divided vertically into five layers based on temperature and altitude above the
Earth‘s surface. Each zone has its own physical and chemical characteristics and
properties such as density, pressure, chemical and electrical and temperature
properties. The five layers are:
1) The troposphere
2) The stratosphere
3) The mesosphere
4) The ionosphere
5) The exosphere
2. Give the composition of the Atmosphere.
Gas
Volume in % Name Formula
Nitrogen N2 78.0
84 Oxygen O2 20.9
46 Argon Ar 0.93
40 Carbon dioxide CO2 0.
0
4
Neon Ne 0.001818
Helium He 0.000524 Methane CH4
0.000179
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Not included in the above dry atmosphere
Water vapor H2O 0.001% to 5%
TMQA.& Part B questions Air Pollution and Control Engineering
186
3. Define Air pollution. (Nov/Dec 2019)
Air pollution is the excessive concentration of foreign matters in the air,
which adversely affects the human beings of the individual or causes damage to
the property.
(OR)
Any substance in the air that causes damages to health and properties.
(OR)
Air pollution is defined as the presence of any solids, liquid or gaseous
matter present in the atmosphere in such concentrations that may or tend to be
injurious to human beings or other living creatures, plants, vegetation.
4. Write the classification of air pollutants. (AU. May/June 2016, Nov/Dec 2017)
i. According to the origin
a. Primary pollutants
b. Secondary pollutants
ii. According to chemical composition
a. Organic pollutants
b. Inorganic pollutants
iii. According to state of matter
a. Gaseous pollutants
b. Particulate matter
5. What are natural contaminants?
The natural contaminants are given below.
Natural fog
Pollen grains
Bacteria
Product of volcanic eruption
6. How inhalation of carbon monoxide affects human health? (AU. May/June
2012)
It reduces the ability of the hemoglobin to carry oxygen to the body tissues.
Neurological disarders take place.
7. Define Sampling. (AU. Nov/Dec 2016)
Sampling - a proper technique uses to acquire a representative sample of
possible contaminated air or gaseous for later evaluation or analysis of the
quantity of pollutants Present.
8. What is Fog or Mist? (AU. May/June 2013)
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187
The fog is defined as visible aerosols in which the dispersed phase in liquid.
The fog is caused by water droplets in the air.
9. Briefly explain the formation of Ozone.
Photochemical (summer smog) forms when pollutants such as nitrogen
oxides and organic compounds react together in the presence of sunlight. A gas
called ozone is formed.
Nitrogen Dioxide + Sunlight + Hydrocarbons
10. List out any three sources of Air Pollution. (AU. Nov/Dec 2016)
i. Stationary sources
Such as power plants, oil refineries, industrial facilities, and factories
ii. Area sources
Such as agricultural areas, cities, and wood burning fireplaces.
iii. Natural sources
Such as wind-blown dust, wildfires, and volcanoes
11. List out the various air pollution caused by nuclear energy program.
(AU. Nov/Dec 2017)
The effect of nuclear pollution is seen on every organism in the
environment from the bacteria to plants to human beings. Nothing is spared. The
immediate and closest to the source, experience Radiation Sickness.
✴ In small doses of 75-200 rems. One experiences vomiting, fatigue and loss of
appetite. At higher exposures of 300 rem and more changes in the blood cells
and bleeding occurs. Above 600 rems there is loss of hair, loss of immunity
usually resulting in death in a few days to weeks.
✴ Radiation causes changes in the cell and gene structure of rapidly multiplying
cells of the body, such as bone marrow, skin, intestines, lymphoid tissue and
embryo.
✴ Those exposed from a distance may not show any immediate symptom. But
the tendency to develop various forms of cancers and have a shortened life span
is seen. Radiation also causes cell mutations which can be transferred to the next
generation.
✴ Foetuses are affected by birth defects and cancers. They may also have a
shorter life span.
✴ Plants die and some shows genetic changes and stunted growth. Animals are
also affected and do not survive for too long.
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188
✴ The radiation in the atmosphere will not dissipate quickly. Every water source
will also be affected. In fact, it may take years or centuries to reach a point where
such a space may become habitable.
✴ An average person will be exposed to about 180 milli rem of radiation in
a year from exposure to natural radiation, medical and dental X rays, Colour
TVs, airport baggage X rays etc.
12. What is the effect of pollution on plants? (AU.May/June2013, May/June
2016 Nov/Dec 2019)
Effects of Air Pollutants on Vegetation
SI.
No.
Air Pollutants Effects on Vegetation
1. Sulfur dioxide Enters into the leaf through stomata.
Excessive exposure causes injury on blade with ivory
colour, brown to reddish brown spots, depending on plant
and environmental conditions.
2. Ozone High concentration causes dark brown to black lesions on
the upper surface of leaves.
3. Suspended
Particulate
Matter
Block the stomata through deposition on leaf surface.
Excessive dust deposition retards the growth of plants.
Automobile exhaust smoke damage lower surface of leaves,
Bronzing and silvering, upper surface shows fleck like
marking.
13. How to Reduce the Pollution?
✴ You can help to reduce global air pollution and climate change by driving a car
that gets at least 35 miles a gallon, walking, bicycling, and using mass transit
when possible.
✴ Replace incandescent light bulbs with compact fluorescent bulbs, make your
home more energy efficient, and buy only energy efficient appliances.
✴ Recycle newspapers, aluminum, and other materials. Plant trees and avoid
purchasing products such as Styrofoam that contain CFCs.
✴ Support much stricter clean air laws and enforcement of international treaties
to reduce ozone depletion and slow global warming.
14. What are the effects of photochemical smog?
i) Eye irritation
ii) Vegetation damage
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189
iii) Visibility reduction
iv) Cracking of rubbers
15. List out the sampling Methods.
Classification of sampling Methods
a. In situ sampling
b. Remote sensing
16. Briefly explain greenhouse effect. (AU. Nov/Dec 2012)
✴ The greenhouse effect is the heating of the surface of a planet or moon due to
the presence of an atmosphere containing gases that absorb and emit infrared
radiation.
✴ Greenhouse gases trap heat within the surface- troposphere system.
✴ This mechanism is fundamentally different from that of an actual greenhouse,
which works by isolating warm air inside the structure so that heat is not lost by
convection.
✴ The greenhouse effect was discovered by Joseph Fourier in 1824, first reliably
experimented on by John Tyndall in 1858, and first reported quantitatively by
Svante Arrhenius.
17. Explain the term global warming. (AU. May/June 2013)
Global warming is the increase in the average temperature of the Earth‘s near-
surface air and oceans since the mid-20th century and its projected continuation.
Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the
last century. The Intergovernmental Panel on Climate Change (IPCC) concludes
that most of the observed temperature increase since the middle of the 20th
century is caused by increasing concentrations of greenhouse gases resulting
from human activity such as fossil fuel burning and deforestation.
18. Define aerosols. (AU. May/June 2013)
An aerosol can be defined as a dispersion of solid and liquid particles
suspended in gas. Atmospheric aerosols, unsurprisingly, refer to solid and liquid
particles suspended in air.
Aerosols are produced by dozens of different processes that occur on land
and water surfaces, and in the atmosphere itself. Aerosols occur in both the
troposphere and the stratosphere, but there are considerable differences in the size
ranges, chemical nature and sources of the aerosols that occur in these two
atmospheric layers.
19. Brief the effect of carbon monoxide on environment.(AU. Nov/Dec 2012,
May/June 2012)
TMQA.& Part B questions Air Pollution and Control Engineering
190
Carbon Monoxide can have a profound effect on the environment as it is
extremely poisonous, and can contribute to very dangerous ground-level air and
ozone conditions.
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191
UNIT II - METEOROLOGY
1. What is the adiabatic lapse rate? (Nov/Dec 2016, Nov/Dec 2019)
As a parcel of air rises in the earth's atmosphere, it experiences lower and
lower pressure from the surrounding air molecules, and thus it expands. This
expansion lowers its temperature. Ideally, if it does not absorb heat from its
surroundings and it does not contain any moisture, it cools at a rate of 1ºC/100 m
rise. This is known as dry adiabatic lapse rate.
2. List out any four sampling methods.
a. Sedimentation
b. Filtration
c. Impingement
d. ESP
3. Define ambient air quality.
A physical and chemical measure of the concentration of contaminants in
the ambient atmosphere. The quality is usually monitored over a specific period.
4. What is the word MINAS stands for? (Nov/Dec 2019)
Minimum National Air Quality Standards.
5. What is Mixing Height?
Height above the earth‘s surface to which related pollutants will extend,
primarily through the action of atmospheric turbulence.
6. Define Fumigation.
The phenomenon in which pollutants that are aloft in the air are brought
rapidly to ground level when the air destabilizes.
7. Define Dispersion.
The mixing of gases contains the highest concentration of pollutant.
8. Write short note on Air monitoring.
The process of detention and measurement of pollutants in air.
9. Define Mass concentration.
Concentration expressed in terms of mass of a substance per unit volume of
gas or liquid.
10. What do you mean by pressure drop?
The differential pressure b/w two points in a system. The resistance to flow
b/w in the two points.
11. Define Relative humidity.
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192
The ratio of the actual vapor pressure of the air to the saturation vapor pressure.
12. What is Inversion? (AU. May/June 2016)
Condition in the atmosphere in which air temperature increases with
elevation, under this condition, the atmosphere is said to be in stable equilibrium.
13. Briefly explain the Box model dispersion. (AU. May/June 2016)
The box model is the simplest of the model types.
It assumes the air shed (i.e., a given volume of atmospheric air in a
geographical region) is in the shape of a box.
It also assumes that the air pollutants inside the box are homogeneously
distributed and uses that assumption to estimate the average pollutant
concentrations anywhere within the air shed.
This model is very limited in its ability to accurately predict dispersion of air
pollutants over an air shed because the assumption of homogeneous pollutant
distribution is much too simple.
14. Briefly explain the Gaussian model. (AU. Nov/Dec 2012)
The Gaussian model is perhaps the oldest (circa 1936) and perhaps the most
commonly used model type.
It assumes that the air pollutant dispersion has a Gaussian distribution,
meaning that the pollutant distribution has a normal probability distribution.
Gaussian models are most often used for predicting the dispersion of
continuous, buoyant air pollution plumes originating from ground-level or
elevated sources.
Gaussian models may also be used for predicting the dispersion of non -
continuous air pollution plumes (called puff models).
The primary algorithm used in Gaussian modeling is the Generalized
Dispersion Equation for a Continuous Point-Source Plume.
15. Explain Lagrangian dispersion model. (AU. May/June 2012)
A Lagrangian dispersion model mathematically follows pollution plume
parcels (also called particles) as the parcels move in the atmosphere and they
model the motion of the parcels as a random walk process.
The Lagrangian model, then calculates the air pollution dispersion by
computing the statistics of the trajectories of a large number of the pollution
plume parcels.
A Lagrangian model uses a moving frame of reference] as the parcels move
from their initial location.
It is said that an observer of a Lagrangian model follows along with the plume.
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16. Briefly explains Eulerian dispersion model. (AU. May/June 2012)
The Eulerian dispersions model is similar to a Lagrangian model in that it also
tracks the movement of a large number of pollution plume parcels as they
move from their initial location.
The most important difference between the two models is that the Eulerian
model uses a fixed three dimensional Cartesian grid as a frame of reference
rather than a moving frame of reference
17. Briefly explain Dense Gas Dispersion Model. (AU. May/June 2016)
Dense gas models are models that simulate the dispersion of dense gas
pollution plumes (i.e., pollution plumes that are heavier than air). The three most
commonly used dense gas models are:
a. The DEGADIS model
b. The SLAB model
c. The HEGADAS model
18. What is Lofting?
A type of plume which occurs when an inversion exits only below the
plume and the plume is inhibited from mixing downward.
19. What is Looping?
A type of plume which has a wavy character. It occurs in a highly unstable
atmosphere because of rapid mixing.
20. What is Chimney?
A structure with an opening or outlet from or through which any air
pollutant may be emitted.
21. Define Coning.
A type of plume which is like a cone. This takes place in a near neutral
atmosphere when the wind velocity is greater than 32km/h.
22. What Is Plume? (A.U. Nov/Dec 2011)
The path and extent in the atmosphere of the gaseous effluent released
from the source, usually a stack.
23. Briefly explain Chimney effect.
The vertical penetration of smog through the inversion layer on the south
slope of the San Gabriel and San Bernardino Mountains caused by the strong
solar heating in the afternoon.
24. Define Fall out.
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A radioactive pollutant in the air caused after the explosion of a nuclear
device, its degree of contamination depending on several factors, such as distance,
wind, and power of the device.
25. What is wind rose? (A.U. May/June 2016, Nov/Dec 2015, Nov/Dec 2016)
A wind rose is a graphic tool used by meteorologists to give a succinct view
of how wind speed and direction are typically distributed at a particular location.
Historically, wind roses were predecessors of the compass rose (found on
charts), as there was no differentiation between a cardinal direction and the wind
which blew from such a direction. Using a polar coordinate system of gridding, the
frequency of winds over a time period is plotted by wind direction, with color
bands showing wind speed ranges. The direction of the longest spoke shows the
wind direction with the greatest frequency.
26. What are the features of wind rose? (Nov/Dec 2019)
1) Presented in a circular format, the modern wind rose shows the frequency of
winds blowing from particular directions over a specified period.
2) The length of each "spoke" around the circle is related to the frequency that
the wind blows from a particular direction per unit time.
3) Each concentric circle represents a different frequency, emanating from zero at
the center to increasing frequencies at the outer circles.
4) A wind rose plot may contain additional information, in that each spoke is
broken down into color-coded bands that show wind speed ranges.
5) Wind roses typically use 16 cardinal directions, such as north (N), NNE, NE,
etc., although they may be subdivided into as many as 32 directions
TMQA.& Part B questions Air Pollution and Control Engineering
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UNIT III - CONTROL OF PARTICULATE CONTAMINANTS
1. Write down the various types of Inertial Separation. (AU. May/June 2013)
✴ Baffle type
✴ Louvre type
2.
✴ Dust trap
Name the common methods of filter cleaning.
(AU. Nov/Dec 2007)
i. Rapping
ii. Shaking
iii. Reverse airflow
iv. Pulse jet
3. State the Principle of cyclone filter. (AU. Nov/Dec 2012)
Control of gas borne pollution particulates, using centrifugal and inertial
methods. A cyclonic separation is a method of removing particulates from an air,
gas or liquid stream, without the use of filters, through vortex separation. The
method can also be used to separate fine droplets of liquid from a gaseous stream.
4. What are the Advantages of ESP?
a) High collection efficiency
b) Particle as small as 0.1 mm can be removed
c) Low maintained and operating cost
d) Low-pressure drop (0.25 – 1.25 cm of water
e) Treatment time is negligible (0.1 – 10. s)
5. What are the Disadvantages of ESP?
High initial cost Space requirement is more possible explosion hazards
during collection of combustible gases or particles Poisonous gas, ozone, is
produce by the negatively charged electrodes during gas Ionization.
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6. Briefly explain Bag filter.
The most common type of collector is tubular type, consisting of tubular
bags. A bag house or bag filter consists of numerous vertical bags. They are
suspended with open ends attached to a manifold.
7. List out the type of Scrubbers.
a) Spray towers
b) Venturi scrubbers
c) Cyclone scrubbers
d) Packed scrubbers
e) Mechanical scrubbers
8) Define Impinger
A sampling instrument adopting the principle of impingement for the
collection of particulate matters.
8. What is Bag house?
An air pollution control device, that traps gas borne particulate by
forcing the gas through filter bags. A bag house, bag filter or fabric filter is an
air pollution control device that removes particulates out of air or gas released
from commercial processes or combustion for electricity generation.
9. Define the term Contaminant.
Unwanted material, usually harmful or of a nuisance value are both. Air
pollution can be defined as the presence of toxic chemicals or compounds
(including those of biological origin) in the air, at levels that pose a health risk.
10. Define Cyclone filter. (AU. Nov/Dec 2012)
A type of particulate collector which depends upon centrifugal force for its action
11. What is meant by Dry bulb temperature?
The actual temperature of the gas measured with a conventional
thermometer. The dry-bulb temperature (DBT) is the temperature of air measured
by a thermometer freely exposed to the air, but shielded from radiation and
moisture. It indicates the amount of heat in the air and is directly proportional to
the mean kinetic energy of the air molecules.
12. Write collection Mechanism of scrubbers. (AU. Nov/Dec 2012, Nov/Dec 2017)
Scrubbers relay on the liquid or gas spray to remove dust particles from the
gas stream. It removes air pollutants by inertia of diffusion impaction, reaction with
absorbent or reagent slurry or absorption into a liquid solvent.
13. Write any two pollution control equipments. (AU. Nov/Dec 2016)
TMQA.& Part B questions Air Pollution and Control Engineering
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a) Electrostatic precipitator
b) Fabric filter
c) Venturi scrubber
d) Cyclone collector
e) Cycling chamber
14. Explain the principle behind settling chambers. (A.U. Nov/Dec 2015)
Gravity Settling Chambers
Particles in the air or gas stream settle due to gravity. This is a simple
particulate collection device using the principle of gravity to settle the particulate
matter in a gas stream passing through its long chamber. The gas velocities in the
settling chamber must be sufficiently low for the particles to settle due to
gravitational force.
15. Write two advantages of Gravity separators. (A.U. Nov/Dec 2019)
1) Low initial cost.
2) Easy to design.
3) Low pressure drop.
4) Low maintenance cost.
16. Write the principle involved in cyclone separator. (A.U. Nov/Dec 2019)
The dust laden gas enters tangentially, receives a rotating motion and generates a
centrifugal force due to which the particulates are thrown to the cyclone walls as
the gas spirals upwards inside the cone (i.e. the flow reverses to form an inner
vortex which leaves flow through the outlet). The particulates slide down the .walls
of the cone and are discharged from the outlet.
TMQA.& Part B questions Air Pollution and Control Engineering
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UNIT IV - CONTROL OF GASEOUS CONTAMINANTS
1. What is adsorption? (AU. May/June 2012)
Removal of impurities from a gas stream by concentration on the surface of
solid or liquid.
2. Explain the process of selection of air pollution control equipment.
(AU. Nov/Dec 2015)
There are a number of factors to be considered prior to selecting a particular
in air pollution control equipment. In general, they can group into three categories:
1) Environmental
2) Engineering
3) Economic
3. What is Incineration?
Combustion of solid, liquid, or gaseous wastes under controlled condition.
Incineration is a waste treatment process that involves the combustion of organic
substances contained in waste materials. Incineration and other high-temperature
waste treatment systems are described as ―thermal treatment‖. Incineration of
waste materials converts the waste into ash, flue gas and heat.
4. What causes of condensation? (AU. Nov/Dec 2012)
✴ Condensation is the formation of liquid drops of water from water vapor.
✴ It is the process which creates clouds, and so is necessary for rain and snow
formation as well.
✴ Condensation in the atmosphere usually occurs as a parcel of rising air expands
and cools to the point where some of the water vapor molecules clump together
faster than they are torn apart from their thermal energy.
5. Define combustion. (AU. May/June 2012)
Combustion is a chemical reaction, chemical that occurs between a fuel
and an oxidizing agent that produces energy, usually in the form of heat and
light.
6. Briefly explain the Control equipment in air pollution.
(AU. Nov/Dec 2012, Nov/Dec 2017)
Any apparatus, devices, equipment or system to control the quality and
manner of emission of any air pollution and includes any devices used for
securing the efficient operation of any industrial plant.
7. Define Due point.
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For air containing water vapor, it is the temperature at which liquid water
begins to condense for a given state of humidity and pressure, as the temperature
is reduced.
8. Define absorption. (AU. Nov/Dec 2016)
Absorption is a process, in which a gaseous pollutant is dissolved in liquid.
9. What is biofiltration? Give examples.
Biofiltration is a pollution control technique using a bioreactorcontaining
living material to capture and biologically degrade pollutants. Common uses
include processing waste water, capturing harmful chemicals or silt from surface
runoff, and microbiotic oxidation of contaminants in air.
Examples:Bioswales, biostrips, biobags, bioscrubbers, Vermifilters and trickling
filters
10. What are catalytic incinerators?
Catalytic incinerators are very similar to thermal incinerators. The main
difference is that after passing through the flame area, the gases pass over a
catalyst bed.
11. List the types of condensation equipments used in air pollution control.
(AU. Nov/Dec 2019)
Condensers used for pollution control are:
1) Contact condensers and
2) Surface condensers.
12. What is bio filtration? (AU. Nov/Dec 2019)
Biofiltration is a pollution control technique using a bioreactor containing living
material to capture and biologically degrade pollutants.
Common uses include processing waste water, capturing harmful chemicals or silt
from surface runoff, and microbiotic oxidation of contaminants in air.
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
UNIT V - INDOOR AIR QUALITY MANAGEMENT
1. List indoor air pollutants.
a) Radon
b) Environmental Tobacco Smoke
c) Biological Sources
d) Carbon Monoxide
e) Nitrogen Dioxide
f) Organic Gases
g) Respirable Particles
h) Formaldehyde
2. What is sick building syndrome?
The term "Sick Building Syndrome" (SBS) is used to describe situations in which building
occupants experience acute health and comfort effects that appear to be linked to time spent in a
building, but no specific illness or cause can be identified.
3. What is noise? (AU. May/June 2012)
In simple terms, noise is unwanted sound. Sound is a form of energy which is emitted by a
vibrating body and on reaching the ear causes the sensation of hearing through nerves.
4. How can noise affect us? (AU. May/June 2016) Temporary
Deafness: This Persists for about 24 hours after exposure to loud noise. Permanent Deafness:
Repeated or continuous exposure to noise of around 100 dB results in permanent
hearing loss.
5. What is the difference between sound and noise?
Noise is unwanted sound. Sound is a form of energy emitted by a vibrating body and on
reaching the ear it causes the sensation of hearing through nerves. Sounds are mechanical waves
of pressure allow us to hear and listen. Noises are unwanted and loud sounds. Noise can also refer
to the static that is heard on the TV or radio during weak signals. Sound and noise are two words
that are often used interchangeably due to their similarities.
6. How can we control the Noise source? (AU. Nov/Dec 2011, Nov/Dec 2015)
Reducing the noise levels from i.
Domestic sectors
ii. Maintenance of automobiles iii. Control
over vibrations
iv. A low voice speaking
v. Prohibition on use of loud speakers vi.
Selection of machinery
7. What are the methods to control noise pollution? (AU. Nov/Dec 2015)
✴ Identify the noise sources from each zone
✴ Find out the noise levels of each zone
✴ Compute Ldn values
✴ Identify the likely causes of noise from noise sources.
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
✴ Develop methodologies to solve the problem
✴ Attempt to solve
8. What are the ambient noise and limits? (AU. May/June 2013, Nov/Dec 2017)
Sounds produced by all vibrating bodies are not audible. The frequency limits of
audibility are from 20 HZ to 20,000 HZ. Noise generation is associated with most of our daily
activities. A healthy human ear responds to a very wide range of SPL from - the threshold of
hearing at zero dB, uncomfortable at 100-120dB and painful at 130-140 Db. Due to the various
adverse impacts of noise on humans and environment noise should be controlled.
9. What is the purpose of frequency analysis?
The frequency analysis allow to separate the main components of the signals by
dividing the frequency range of interest into smaller frequency bands using a set of filters.
10. List out various resources of Noise Pollution.
(AU. May/June 2013, 2016, Nov/Dec 2016)
S.NO. Source Noise level in dB
1. Air compressors 95-104
2 Quiet garden 30
3 110 KVA diesel generator 95
4 Ticking clock 30
5 Lathe Machine 87
6 Computer rooms 55-60
7 Milling machine 112
8 Type institute 60
9 Oxyacetylene cutting 96
10 Printing press 80
11. What are the impacts of noise? (AU. May/June 2016)
a) Physiological effects b) Loss of
hearing
c) human performance
d) Nervous system damage
e) Annoyance
f) Sleeplessness
g) Damage to material
12. What are the noise exposure limits in a workspace environment?
Regulations prescribe that, noise level of 90 dB (A) for more than 8 hr continuous
exposure is prohibited. Persons who are working under such conditions will be exposed to
occupational health hazards.
13. Write short notes on Decibel, dB and Ldn. (AU. Nov/Dec 2012)
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
DECIBEL is measurement unit of sound, represented by dB. The day night
equivalent noise levels of a community can be expressed as -Ldn ,
14. Write short notes on Infrasonic and Ultrasonic. (AU. May/June 2012)
Infrasonic: The sound of frequency less than 20 HZ. Ultrasonic: The
sound of frequency more than 20,000 Hz
15. What are the equipment used in the measurement of noise levels
Sound level meter
✴ Type-0: Laboratory reference standard
✴ Type-1: Lab use and field use of specified controlled environment
✴ Type-2: General field use (Commonly used)
✴ Type-3: Noise survey mpulse meters For measurement of impulse noise levels, Example:
Hammer blows, punch press strokes etc.
16. What is noise? (AU. Nov/Dec 2016)
Noise is defined as unwanted sound. A sound might be unwanted because it is loud,
distracting, or annoying.
17. How is noise measured?
Literally speaking, noise can‘t be measured directly, since there is no instrument for
objectively detecting how ―unwanted‖ something is. What can be measured is the sound level, a
quantification of a sound pressure or intensity and related to its loudness. Sound level is
measured in decibels (dB), by a device called a sound level meter.
18. What is the loudest sound possible?
Sound is normally carried in the air as a pressure wave. When the pressure of a sound
wave becomes as high as the air pressure itself, the sound becomes a shock wave.
Normal air pressure at sea level is 14.7 pounds per square inch (psi), or 101,325 Pascals (Pa),
which is equivalent to 194 decibels (dB). So 194 dB is the loudest sound possible in air at sea
level; beyond that point it becomes a shock wave (The sound waves that are transmitted through
water or other substances would have different limits.)
19. What is a decibel?
The typical decibel levels of some common sounds? A whisper is 30 dB, conversational speech
is 60 dB, and someone shouting at you from an arm‘s length away is 85 dB. Noise levels of home
appliances range from 50 dB (a refrigerator) to 95 dB (a food processor).
Lawn equipment and power tools have noise levels of 80–120 dB.
20. How many decibels can the human ear handle ?
✴ Immediate and irreversible nerve damage can be caused by sounds at 140 dB or higher (120
dB in young children).
✴ Damage also occurs at lower sound levels, and this harm accumulates over time.
✴ Any sound above 85 dB can cause wear and tear on your ears that reduces your hearing
acuity over time.
21. What are the effects of noise on human health? (AU. May/June 2016)
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
the noise has direct physiological effects such as hearing damage (including hearing
loss and tinnitus, or ringing in the ears), as well as cardiovascular and hormonal disturbances.
Indirect effects include sleep loss, interference with concentration and learning, mood changes
and aggression, and social isolation.
22. How does noise affect babies and children?
Because the ear canal of a young child is smaller than an adult‘s, sound pressure is up to
20 dB greater than that in an adult ear. In addition to the threat to a child‘s hearing, noise causes
physiological and mental stress, and significantly impacts learning and cognitive development.
Background noise also interferes with speech perception and language acquisition.
23. What is “white noise”?
White noise is a sound similar to radio static, or the sound a fan makes, that is often used to
mask unpleasant sounds. Some people find it helpful for sleeping, and it can be a soothing sound
for babies.
24. What are the most common sources of noise pollution?
Worldwide, the most common sources of noise pollution are cars, trucks, and other motor
vehicles. Planes and trains also contribute to noise pollution. Other sources include factory
machinery, power tools, and construction equipment.
25. What problems does noise pollution cause for people?
The World Health Organization (WHO) cites seven categories for the way noise adversely
affects human health:
a) Noise-induced hearing impairment
b) Interference with speech communication c) Sleep
disturbances
d) Cardiovascular and physiological effects
e) Mental health effects
f) Effects on performance of tasks
g) Annoyance and effects on behavior
26. What are the laws regarding noise pollution ?
✴ Occupational noise is treated as a health and safety issue and is regulated at the state or
national level in many countries.
✴ Community noise is typically regarded as a nuisance issue rather than a matter of health, and
is normally regulated at local levels of government.
✴ The regulations and levels of enforcement vary widely across different communities, and
worldwide.
✴ Noise-generating products such as automobiles and aircraft may be controlled by industry
regulations, and building codes may set requirements for reducing sound transmission in new
building construction projects.
27. What is thershold shift? (AU. Nov/Dec 2012, Nov/Dec 2016)
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
The threshold shift is a temporary shift in the auditorythreshold. It may occur suddenly
after exposure to a high level of noise, a situation in which most people experience reduced hearing.
A temporary threshold shift results in temporary hearing loss.
28. Define indoor air pollution. (A.U. Nov/Dec 2019)
Pollutants are any harmful contaminants in the air; therefore, indoor air pollution is when
pollutants from things such as gases and particles contaminate the air indoors.
29. Write the ambient air quality standards in respect of noise. (A.U.Nov/Dec 2019)
PART – B QUESTIONS
UNIT I - INTRODUCTION
1. Explain in detail about the structure and composition of the atmosphere.
2. List out the various air pollutants, their sources and its effect on both plant and
human being. (AU. May/June 2012, May/June 2013, Nov/Dec 2011, Nov/Dec 2013)
3. Write the effects of air pollution on human beings. (AU. May/June 2016, May/June 2013,
Nov/Dec 2013)
4. What is global warming? Discuss its occurrence pollutants responsible and impacts. (AU.
May/June 2013, May/June 2012, Nov/Dec 2013)
5. Write the causes, effects and control of ozone layer depletion. (AU. May/June 2016)
6. Explain the economical impacts of air pollution. Give an example. (AU. Nov/Dec 2011,
Nov/Dec 2012)
7. a) Write the sources and classification of pollutants.(A.U. Nov/Dec 2019)
b) Discuss the effects of CO and PM2.5
8. a) Write the National Ambient Air Quality standards for industrial, residential and ecologically
sensitive areas. (A.U. Nov/Dec 2019)
b) Explain the structure of the atmosphere.
UNIT II - METEOROLOGY
1. What are the meteorological factors influencing the air pollution? Explain briefly. (Nov/Dec
2011, Nov/Dec 2012, May/June 2013)
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
2. With neat sketch, explain the effect of lapse rate on plume behavior. (May/June 2016, May /
June 2012)
3. Explain Gaussian dispersion model with assumption, merits and demerits. (May/June 2012,
Nov/Dec 2012, May/June 2016)
4. What are dispersion models? State the types and explain them. (May/June 2013, Nov/Dec 2015)
5. Explain the plume behavior form a stack with respect to the different prevailing lapse rate. Use
neat sketches. (May/June 2012, Nov/Dec2015)
6. Explain the factors affecting dispersion of air pollutants. (May/June 2016)
7. a) Explain with neat sketch the types of flume behavior. (Nov/Dec2019)
1. Explain the types of inversions.
8. a) Write the assumptions of Gaussian Plume model. (Nov/Dec2019)
a. b) Explain the meteorological parameters influencing the air pollution.
UNIT III - CONTROL OF PARTICULATE CONTAMINANT
1. With neat sketch, explain the working principle of electrostatic precipitator. (AU. May/June
2016, May / June 2012, Nov/Dec 2012)
2. How does a bag house filter work? What are the positives and negatives of filtration process?
(AU. Nov/Dec2012, May/June 2013)
3. Suggest an air pollution control plan for a cement industry and justify. (AU. Nov/Dec 2011,
Nov/Dec 2012)
4. Explain the process of selection of air pollution control equipment. (AU. Nov/Dec 2015)
5. Explain the principle of operation and working of a settling chamber. How its efficiency can be
improved? (AU. May/June 2013)
6. Explain with neat sketch the working principle, advantages and disadvantages of an Electrostatic
precipitator. (Nov/Dec2019)
7. a) Explain the approaches to air pollution control. (Nov/Dec2019)
8. Discuss the factors to be considered in selection of equipment for control of particulate
contaminants.
UNIT IV - CONTROL OF GASEOUS CONTAMINANTS
1. Explain how gaseous pollutants are controlled using the principle of adsorption and absorption.
(AU. May/June 2016, May/June 2013, Nov/Dec 2012)
2. Explain the process of selection of air pollution control equipment. (AU. Nov/Dec 2015)
3. Discuss the principles of control technologies for gaseous pollutants with the help of neat
sketches.
4. Discuss in brief about pollution control for Cement Industry and Pulp and Paper Industry.
5. Elaborate the role of Biofiltration technique in the air pollution control
V.S.B ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING
6. Explain the principle of absorption and adsorption for the control of gaseous pollutants. (AU.
Nov/Dec 2019)
7. Explain with neat sketch the working principle of an incinerator with its advantages and
disadvantages. (AU. Nov/Dec 2019)
UNIT V - INDOOR AIR QUALITY MANAGEMENT
1. Explain the effects and assessment of Noise Pollution and list the standards.
(AU. Nov/Dec 2015, May/June 2016)
2. Make a detailed discussion on effects of Noise Pollution. (AU. Nov/Dec 2012,
May/June 2013, May/June 2016)
3. Explain the different noise control methods. (AU. Nov//Dec 2012, May/June
2013, Nov/Dec 2015)
4. What is a noise rating system? What is its importance? (AU. May/June 2012,
Nov/Dec 2012, Nov/Dec 2011)
5. Describe the sources of Noise Pollution. (AU. May/June2012, Nov/Dec2015)
6. Explain the methods to control noise pollution in industrial area. (AU. May/June 2016)
7. Write a detailed note on sources, effects, standards and control of indoor air pollution.
8. a) Write the sources of indoor air pollution. (AU. Nov/Dec 2019)
b) What are the symptoms of sick building syndrome?
9. Explain the effects of noise on human beings. Write the methods to eliminate or reduce noise.
(AU. Nov/Dec 2019)
10. Suggest an air pollution control plan for Chennai metropolitan city. (AU. Nov/Dec 2019)
11. Discuss the control and preventive measures to be taken for nose pollution in a commercial
complex. (AU. Nov/Dec 2019)
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