ABSTRACT The camp was held at a village near steel plant, Panruti post, Kancheepuram District. The camp took place for a period of 5 days in Kunnavakkam village. We learnt to find the area of the given place by Triangulation and Trilateration, Longitudinal section and Cross section of a proposed roadway, level of a large area by Grid contouring and radial contouringand the use of Total Station to find the given area. All the experiments were performed at Kunnavakkam village. The area was nearly 100 acres and hence no difficulty was faced by us to perform the experiments. www.studentsfocus.com
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ABSTRACT
The camp was held at a village near steel plant, Panruti post, Kancheepuram District. The camp took place for a period of 5 days in Kunnavakkam village.
We learnt to find the area of the given place by Triangulation and Trilateration, Longitudinal section and Cross section of a proposed roadway, level of a large area by Grid contouring and radial contouringand the use of Total Station to find the given area. All the experiments were performed at Kunnavakkam village. The area was nearly 100 acres and hence no difficulty was faced by us to perform the experiments.
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CONTENTS
EX.NO NAME OF THE EXPERIMENT PAGE NO 1. TRIANGULATION 2. TRILATERATION 3. GRID CONTOURING 4. RADIAL CONTOURING 5. TOTAL STATION
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TRIANGULATION AND TRILATERATION
The method of surveying called triangulation is based on the trigonometric proposition that if one side and two angles of a triangle are known, the remaining sides can be computed. The vertices of the triangles are known as triangulation stations. The side of the triangle, whose length is predetermined, is called the base line.
A triangulation system also consists of a series of joined or overlapping triangles. However, for trilateration the lengths of all the sides of the triangle are measured and few directions or angles are measured to establish azimuth. Trilateration has become feasible with the development of electronic distance measuring (EDM) equipment which has made possible the measurement of all lengths with high order of accuracy under almost all field conditions.
OBJECTIVE OF TRIANGULATION AND TRILATERATION SURVEYS
The main objective of triangulation or trilateration surveys is to provide a number of stations whose relative and absolute positions, horizontal as well as vertical, are accurately established. More detailed location or engineering survey is then carried out from these stations. The triangulation surveys are carried out
9 To establish accurate control for plane and geodetic surveys of large areas, by terrestrial methods,
9 To establish accurate control for photogrammetric surveys of large areas, 9 To assist in the determination of the size and shape of the earth by making
observations for Latitude, longitude and gravity. CLASSIFICATION OF TRIANGULATION AND TRILATERATION SYSTEM
x First order: Determine the shape and size of the earth or to cover a vast area
x Second order: This consists of a network within a first order triangulation.
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x Third order: It is a framework fixed within and connected to a second order triangulation system to immediate control for locating surveys.
LAYOUT FOR TRIANGULATION:
The triangles in a triangulation system can be arranged in a number of ways.
x Single chain of triangles x Double chain of triangles x Braced quadrilaterals x Centered triangles and polygons
Single chain of triangles:
When the control points are required to be established in a narrow strip of terrain such as a valley between ridges, a layout consisting of single chain of triangles. It does not involve observations of long diagonals. This system does not provide any check on the accuracy of observations.
Braced quadrilaterals:
A triangulation system consisting of figures containing four corner stations and observed diagonals. This system is treated to be the strongest and the best arrangement of triangles, and it provides a means of computing the lengths of the sides using different combinations of sides and angles.
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Double chain of triangles:
This arrangement is used for covering the larger width of a belt. This system also has disadvantages of single chain of triangles system.
Centered triangles and polygons:
A triangulation system which consists of figures containing interior stations in triangle and polygon is known as centered triangles and polygons. Though this system provides checks on the accuracy of the work, generally it is not as strong as the braced quadrilateral arrangement. Moreover, the progress of work is quite slow due to the fact that more settings of the instrument are required.
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EX. NO. 01
DETERMINATION OF AREA BY TRIANGULATION METHOD
AIM:
To determine the area of the given plot using the method of triangulation.
DESCRIPTION:
Triangulation is the process of establishing horizontal control in the surveying. The triangulation system consist of number of inter connected triangles in which the length of the base line and the triangle are measured very precisely.
EQUIPMENTS REQUIRED:
x Theodolite with tripod stand x Ranging rod x Tape x Arrow
FORMULA USED:
Sine formula:
asin A =
bsin B =
csin C
For calculating the sides of a triangle,
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AB2 = AC2 + BC2 – 2*AC*BC*cosθ
Θ is the angle between ACB
TO FIND AREA:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐
s =(𝑎+𝑏+𝑐)2
, a, b and c sides of a triangle
PROCEDURE:
x The base line is selected and marked as P and Q at 25m distance apart. x The other station points namely A,B,C,D where selected around the base
line PQ x Ranging rods are fixed at each point and now the instrument is placed over
the station P and all other adjustments were made x Then from P the ranging rod at the station Q is sighted and angles were
noted keeping the instrument. x At face left similarly from station P all the other points were sighted and the
angles were measured. After that the angles were noted by changing the face of the instrument to face right.
x Then the instrument is shifted to station Q and the initial adjustments are done.
x Repeat the same procedure carried out at the station P and the angles were recorded.
x The interior angles were calculated and drawings are drawn. Area are calculated using the formula
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DATE
BATCH NO
TITLE DETERMINATION OF AREA BY SIMPLE TRIANGULATION METHOD
STAFF NAME
INSTRUMENT NO
Instrument sight
Sight to
Face left swing right Face right swing left Total mean A B mean A B mean
* ‘ ‘’ “ ‘ “ * ‘ “ * ‘ “ * ‘ “ * * ‘ “
S1
A B S2 G H
S2 S1 B C S3 F G
S3 S2 C D
CALCULATION:
IN TRIANGLE S1S2B:
asin θ1 =
BS2sin θ2 =
SB1sin θ3
BS2 = m
Sb1 = m
s =(𝑎+𝑏+𝑐)2
= 𝑚A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
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IN TRIANGLE S2S3C:
asin θ1 =
CS2sin θ3 =
CS3sin θ2
CS2 = 80.23m
CS3 =m
s =(𝑎+𝑏+𝑐)2
= 𝑚
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
IN TRIANGLE S1S2G:
asin θ1 =
GS1sin θ3 =
GS2sin θ2
GS1 = m
GS2 = m
s =(𝑎+𝑏+𝑐)2
= 𝑚
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
IN TRIANGLE S2S3F:
asin θ1 =
FS2sin θ2 =
FS3sin θ3
FS2 = m
FS3 = m
s =(𝑎+𝑏+𝑐)2
= 𝑚
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
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IN TRIANGLE BS2C:
BC2 = BS22+ CS2
2 – 2*BS2 * CS2 COSθ
BC2 =
s =(𝑎+𝑏+𝑐)2
= m
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
IN TRIANGLE S2GF:
GF2 = FS22 + GS2
2 – 2*FS2 * CS2 COSθ
GF2 =
s =(𝑎+𝑏+𝑐)2
= m
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
IN TRIANGLE S1GH:
GH2 = HS12 + GS1
2 – 2*HS1 * GS1 COSθ
GH2 =
s =(𝑎+𝑏+𝑐)2
= m
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
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IN TRIANGLE S1AB:
AB2 = AS12 + BS1
2 – 2*AS1 * BS1 COSθ
AB2 =
s =(𝑎+𝑏+𝑐)2
= m
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
IN TRIANGULE S1AH:
AS1= 30m
HS1= 52.5m
s =(𝑎+𝑏+𝑐)2
= m
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 = m2
TOTAL AREA = 1+2+3+4+5+6++7+8+9 (TRIANGLE VALUE)
TOTAL AREA = m2
RESULT:
The area of the given plot = m2
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EX. NO. 02
DETERMINATION OF AREA BY TRILATERATION METHOD
AIM:
To determine the distance between the given station points using the method of trilateration and area enclosed by the station points.
DESCRIPTION:
Trilateration is the method of calculating the distance between the station points by running a closed traverse
EQUIPMENT REQUIRED:
x Theodolite x Ranging rod x Leveling staff x Cross staff x Arrows x Pegs
FORMULA USED:
Horizontal distance
D = KS COS2θ + C COSθ
K = multiple constants =100
C= additive constants = 0
S = staff intercept (top hair – bottom hair)
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AREA OF THE TRIANGLE:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 s =(𝑎+𝑏+𝑐)2
, a, b and c sides of a triangle
PROCEDURE:
x Mark the given points A,B,C,D,E,… by using peg or arrows in such a way that it is possible to see those points from any point
x Then the instrument is placed in such a way that it is centre to all the points and also visible from the selected points.
x The initial adjustment are done for accuracy in the survey x Then the point A is forced and then the vertical angle and the top, middle
and top hair readings are taken by placing the leveling staff at point A. x The vertical and the top, middle and the top hair reading are taken for all
the given points x Then the instruments is set any point and the distance and the vertical
angle between the adjacent points are taken x Thus we get a polygon whose sides are known or multiple triangle whose
sides are drawn x By using the given dimensions and by using the triangle formulas the area
can be calculated.
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TABULATION:
DATE BATCH NO EXERCISE DETERMINATION OF AREA BY TRILATERATION METHOD
STAFF NAME INSTRUMENT NO STATION
PT SIGHT
TO STADIA HAIR READING VERTICAL
POINT VERTICAL ANGLE TOP MIDDLE BOTTOM
O
A B C D E F
A B F
E D F
C D B
CALCULATION:
Horizontal distance = KS COS2θ + C COSθ
Where C=0
OA = KS COS2θ + C COSθ
OA=
OB= KS COS2θ + C COSθ
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OB=
OC = KS COS2θ + C COSθ
OC=
OD = KS COS2θ + C COSθ
OD=
OE = KS COS2θ + C COSθ
OE=
OF= KS COS2θ + C COSθ
OF=
AB= KS COS2θ + C COSθ
AB=
AF = KS COS2θ + C COSθ
AF=
ED = KS COS2θ + C COSθ
ED=
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EF = KS COS2θ + C COSθ
EF =
CD = KS COS2θ + C COSθ
CD=
CB = KS COS2θ + C COSθ
CB=
TO FIND THE AREA:
IN TRIANGLE AOB:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 =
s =(𝑎+𝑏+𝑐)2
=
IN TRIANGLE BOC:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 =
s =(𝑎+𝑏+𝑐)2
=
IN TRIANGLE COD:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 =
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s =(𝑎+𝑏+𝑐)2
=
IN TRIANGLE DOE:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 =
s =(𝑎+𝑏+𝑐)2
=
IN TRIANGLE EOF:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 =
s =(𝑎+𝑏+𝑐)2
=
IN TRIANGLE AOF:
A= 𝑠 𝑠 − 𝑎 𝑠 − 𝑏 𝑠 − 𝑐 =
s =(𝑎+𝑏+𝑐)2
=
TOATAL AREA = A1 +A2 + A3 + A4+ A5 +A6
A=
RESULT:
The area of the given plot is m2
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EX. NO.03
CONTOURING
Contour lines are imaginary line on the ground joining the points of equal elevation. It is a line in which the surface of ground is intersected by a level surface.
CONTOUR INTERVAL:
The vertical distances between two consecutive contours are called as contour interval. The contour interval is kept constant for a contour plan, otherwise the general appearance of the map will be misreading.
x Nature of the ground x The scale of the map x Purpose and extend of the survey x Time and expense of field and office work
CHARACTERISTICS OF CONTOUR:
The following characteristics features may be used while plotting or reading a contour plan or topographic map.
x Two contour lines of different elevations can write to form one line only in the case of a vertical cliff.
x Contour lines close together indicate steep slope. They indicate a gentle slope if they are far apart.
x A contour passing through any point is perpendicular to the line of steepest slope at that point.
x A closed contour line with one or more higher ones inside and it represents a hill.
x Two contour lines having the same elevation cannot write and continue split into two lines.
x A contour line must close upon itself, not necessarily within the limits of the map.
x Contour lines cross a watershed or ridge line at right angles.
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x Contour lines close a valley line of right angles.
Methods of locating contours:
a) The direct method b) The indirect method
(a) The direct method:
As in the indirect method, each contour is located by determining the positions of a series of points through which the contour passes. The operation is also sometimes called tracing out contours. The field work is two-fold.
1. Vertical control : Location of points on contour 2. Horizontal control : Survey of those points
(b) The indirect method:
In this method, some guide points are selected along a system of straight lines and their elevations are found. The points are taken plotted and contours are drawn by interpolation. These guide points are not except by coincidence.
The following are some of the indirect method of locating the ground points.
1) By squares 2) By cross sections 3) Tachometric method
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EX.NO.04 (a)
GRID CONTOURING
AIM:
To draw the contour map for the given area
DESCRIPTION:
A map without relief representation is simply a plan on which relative positions of details are only shown in horizontal phase. Relative heights of various points on the map may be represented by one of the methods of contour.
SQUARE METHOD:
It is the indirect method of contouring. Here the entire area is divided into number of square sides which may vary from 4m-48m, depending upon nature of the ground, the contour interval and the scale of the plan.
EQUIPMENTS REQUIRED:
x Theodolite with tripod stand x Ranging rod x Leveling staff x Arrows x Cross staff x Tape or chain
PROCEDURE:
x The site for block countering is selected by through study. The dimension of block counter size is selected accordingly.
x Then the area is divided into blocks of the size 3m*3m by using cross staff, chain and ranging rod.
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x The instrument is placed in such a place where maximum reading can be taken on the intersection points
x Readings taken at the intersection points are entered in the field book. x Change points are provided wherever needed. After taking the readings,
the RL of each point is calculated by height of collimation method or by rise and fall method.
x All reduced levels are plotted in A2 drawing sheet of suitable scale.
The points having same reduced levels are connected and finally we observe a contour map. The contour of the desired values in interpolated.
DATE BATCH NO. TILTE GRID CONTOURING STAFF NAME INSTRUMENT NO.
The block size of 3m*3m was drawn and reduced level at each intersection was entered. Smooth curves of various lines were drawn connecting points of equal elevation and the contour map was prepared.
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EX.NO.04 (b)
CONTOURING – RADIAL CONTOURING
AIM: To prepare contour map for the given area.
INSTRUMENTS REQUIRED: 1. Theodolite
2. Ranging rod
3. Chains
4. Arrows
5. Pegs
PRINCIPLE: This method is suitable for countering the area of long strip undulations
where direct chaining is difficult.
FORMULA USED: Reduced level of the instrument = Bench mark + staff reading on bench mark –
Height of Instrument
Horizontal distance=D=KS cos2 θ +cos θ
S=staff intercept
Vertical distance=Dtan θ
Reduced level of any point= Reduced level of the instrument-- staff reading -
Vertical distance
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PROCEDURE:
x Range out the radial line from a common centre at known angular interval.
x Fix arrows on the radial lines at equal distances of 3m or 5m.
x Set up the instrument at any convenient place to cover the maximum points.
x Hold the leveling staff in the place of arrows.
x Note down the vertical angels and the hair readings and enter it correctly.
x Repeat the same procedure for other radial lines.
x Similarly shift the instrument s tat ion to other convenient place and c over
the entire area.
OBSERVATION AND TABULATION BATCH NO
TITLE RADIAL CONTOURING
STAFF NAME
INSTRUMENT NO
Instrument AT
Bearing in
Degree
Sight To
Horisontal Distance B.S I.S F.S H.I R.L Remarks
O
0
100 B.M
30°
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O
60°
90°
120°
1500
2400
2700
.
3000
3300
3600
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RESULT:
The block size of 3mx3m was drawn and reduced level at each intersection
was entered. Smooth curves of various lines were drawn connecting point of equal
elevation and the contour map was prepared.
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TOTAL STATION
INTRODUTION: Total station is an electronic/ optical instrument mainly applied in constrution
and civil engineering field. Angles, distance, coordinates and many advanced measurement are accomplied by using trigonometry and triangulation. Downloading and uploading data are available.
PURPOSE AND USES:
x Large and high resolution screen guarantees a clear display
x Measure up to 100m in the reflector less mode
x Extended internal memory accepts up to 50000 point
x Handly EDM head
x Electronic auto compensator
x Equipped with advanced measurement programs and practical software
x Possibility of red laser centering
x Red laser directing ensures pinpoint accuracy in reflector less measurement
x Easy and directoperation with the alphanumeric keyboard and the function keys
x Long battery life up to 30 hours for angle measurement only
x Rugged,durrable, water and dust resistant design
x Technical specifications.
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ANGLE MEASUREMENT (HZ.V)
Accuracy 5"
Method grating disk
Min. reading 1"
Standard deviation 2"
Compensation vertical axis
Compensating range ±3'
Level parameter:
Circular level 8'/2mm
Plate level 30"/2mm
TELESCOPE
Magnification 30x Image erect
Field of view 10 30'(2.6%)
Min. focus 1.5m
Optical aperture 45mm
Length of sleeve 150mm
Resolution 3"
Distance of circles 71mm
DISTANCE MEASUREMENT
x Min. reading 1 mm
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Reflector:
Measurement range (good condition)
Single prism 4000m
Triple prism 7000m
Measurement accuracy ± (3+2ppm.D) mm
Measurement time:
x Fine measurement mode (repeat) about 1.8 sec (first time 2.5 sec) x Tracking measurement mode about 0.4 sec (first time 1.5 sec)
Atmospheric correction:
x Input range -499ppm ̰ +499mm (step 1ppm) x Prism constant correction -99mm ̰+99mm(step 1ppm)
Reflector less:
x Measurement range (Kodak white) 100m x Measurement accuracy ±5mm
Measurement time:
x Fine measurement mode (repeat) about 1.8 sec (first time 3 sec) x Tracking measurement mode about 0.5 sec (first time 2 sec)
DISPLAY:
x Screen type 4-line dot matrix LCD with backlight x Display unit Double sides
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PHYSICAL SPECIFICATIONS
Battery power:
Voltage DC 7.2V
Capacity:
Distance and angle
Measurement
Angle measurement
Lithium battery BDC 40L 4.0AH 4.5h 30h
Temperature -200c
Dimension: 190mmx210mmx350mm
Net weight: 0.6Kg
OTHERS
Interface RS 232C
Water proof /dust proof protection IP54
Standard specifications:
Main unit 1
Software 2
RS 232 data Cable 1
Rechargeable battery 2
Battery charger 1
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Car charger 1
Tool kit 1
Dryer 1
Lint- free cloth 1
Brush 1
Screwdriver 1
Rain protector 1
GRAPHICAL VIEW:
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EX.NO.05
DETERMINATION OF AREA BY USING TOTAL STATION
AIM:
To determine the area of the polygon by using total station.
APPARATUS REQUIRED:
x Total station x Prism x Stand x Prism stand
DESCRIPTION:
It is electronic instrument that has a large accuracy and are mostly preferred in large projects. It is less time consuming and overcomes human errors over a great extent making things easier.
PROCEDURE:
x Select the suitable station point such that all the point of the polygon is visible clearly
x Place the total station and level it and center point of the station is noted
x Take the reference point and set the co ordinate (0,0,and 0) x Place the prism on the first point and focus it and measure it for
getting coordinate of that point x Similarly, get the coordinate of different points of the polygon
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x Finally, place the prism at the first point and measure it for complete closed polygon
x Go to graphical view and see the polygon x Go to calculation 2d areaand get area of the polygon.
STEPS TO BE FOLLOWED:
FLOW CHART
Level it
Change it made B
Set the coordinate (0, 0, 0) on reference point
Place the prism at point
Focus it and measure
Similarly for all the point and get coordinates
Finally, place the prism at first point for closed polygon