DARSHAN INSTITUTE OF ENGINEERING & TECHNOLOGY RAJKOT GEOTECHNICAL ENGINEERING (3130606) LAB MANUAL DEGRRE CIVIL ENGINEERING SEMESTER III Name of Student Roll No Enrollment No Class Department of Civil Engineering Geotechnical Engineering Laboratory Darshan Institute of Engineering and Technology Rajkot
71
Embed
DARSHAN INSTITUTE OF ENGINEERING & TECHNOLOGY … · Constant Head Permeability Test A) 26 Variable/Falling Head Permeability B) Test 29 5. Determination of compaction characteristics
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
DARSHAN INSTITUTE
OF
ENGINEERING & TECHNOLOGY RAJKOT
GEOTECHNICAL ENGINEERING
(3130606)
LAB MANUAL
DEGRRE CIVIL ENGINEERING
SEMESTER III
Name of Student
Roll No
Enrollment No
Class
Department of Civil Engineering
Geotechnical Engineering Laboratory
Darshan Institute of Engineering and
Technology Rajkot
INDEX
Sr.
No Name of Experiment
Page
No. Date Sign
Physical / Index Property Tests on Soils
1. Grain Size Distribution - Sieve Analysis 3
2. Determination of Atterberg limits of fine-grained soils --
A) Liquid Limit Test (Casagrande Method) 7
B) Plastic Limit Test 12
C) Shrinkage Limit Test 15
3. Determination Of In Situ Dry Density --
A) Core Cutter Method 20
B) Sand Replacement Method 23
Engineering Property Tests on Soils
4. Determination of Coefficient of Permeability of Soils
A) Constant Head Permeability Test 26
B) Variable/Falling Head Permeability Test 29
5. Determination of compaction characteristics of soils --
A) Compaction Test (Light & Heavy Compaction Test) 32
6. Box Shear Test (Direct Shear Test) 35
7. Laboratory Vane Shear Test 39
8. Unconfined Compression Test 42
9. Triaxial Test 46
10. Consolidation Test 51
11. Standard Penetration Test (SPT) 59
12. California Bearing Ratio Test (CBR) 64
3 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 1.
GRAIN SIZE DISTRIBUTION - SIEVE ANALYSIS (IS: 2720 PART- 4)
OBJECTIVE:
To determine grain size distribution for given soil sample by sieve analysis.
NEED AND SCOPE
The grain size analysis is widely used in classification of soils. The data obtained
from grain size distribution curves is used in the design of filters for earth dams and
to determine suitability of soil for road construction, air field etc. Information
obtained from grain size analysis can be used to predict soil water movement
although permeability tests are more generally used.
APPARATUS:
Balance: Sensitive to 0.1% of the weight of sample to be weighed.
IS Sieves: 4.75mm, 2.00mm, 1.00mm, 600 µ, 425 µ, 300 µ, 150 µ, to 75 µ.
Brushes - sieve brushes and a wire brush or similar stiff brush.
Mortar with a Rubber Covered Pestle
Mechanical Sieve Shaker (Optional), Riffle & Pan.
Sieves Set Retained Material on Sieve
4 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Preparation of Sample:
The soil sample received from the field shall be prepared as-specified in IS: 2720
(Part I)-1983. The soil fractions retained on and passing 4.75-mm IS Sieve shall
be taken separately for the analysis.
Mass of Soil Required for Sieve Analysis
PROCEDURE:
Analysis by Wet Sieving - The portion of the soil passing 4.75-mm IS Sieve obtained
as given in shall be oven-dried at 105 to 110°C. The oven-dried material shall then
be riffled so that a fraction of convenient mass is obtained. This shall be about 200 g
if a substantial proportion of the material only, just passes the 4.75-mm IS Sieve or
less if the largest size is smaller. The fraction shall be weighed to 0. 1 percent of its
total mass and the mass recorded. The riffled and weighed fraction shall be spread
out in the large tray or bucket and covered with water.
Two grams of sodium hexametaphosphate or one gram of sodium hydroxide and one
gram of sodium carbonate per litter of water used should then be added to the soil.
The mix should be thoroughly stirred and left for soaking.
The soil soaked specimen should be washed thoroughly over the nest of sieves,
nested in order of their fineness with the finest sieve (75-micron IS Sieve) at the
bottom. Washing shall be continued until the water passing each sieve is substantially
clean. Care shall be taken to see that the sieves are not overloaded in the process.
Maximum Size of Material Present In
Substantial
Quantities in (mm)
Mass To Be Taken For Test In
(kg)
75 60
40 25
25 13
19 6.5
12.5 3.5
10 1.5
6.5 0.75
4.75 0.4
5 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
The fraction retained on each sieve should be emptied carefully without any loss of
material in separate trays. Oven dried at 105 to 110°C and each fraction weighed
separately and the masses recorded.
Alternatively, the soaked soil specimen may be washed on the 75-micron IS Sieve
until the water passing the sieve is substantially clean. The fraction retained on the
sieve should be tipped without loss of material in a tray, dried in the oven and sieved
through the nest of sieves, either by hand or by using mechanical sieve shaker. The
fraction retained on each sieve should be weighed separately and the masses
recorded.
Make a grain size distribution curve by plotting sieve size on log scale and percent
finer on ordinary scale
Read off the sizes corresponding to 60%, 30% and 10% finer. Calculate the
uniformity coefficient (Cu) and the curvature coefficient (Cc) for the soil.
OBSERVATION TABLE:
Weight of soil sample taken for the test W = gm.
Sieve Size
(mm)
Soil Retained
(gm)
Percent
Retained (%)
Cumulative
Percent Retained (%)
Percent Finer
(%)
4.75 mm
2.00 mm
1.00 mm
600 µ
425 µ
300 µ
150 µ
75 µ
Pan
6 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Particle Size Distribution Curve
D60 = mm
D30 = mm
D10 = mm
Coefficient of Uniformity CU = D60/D10 = .
Coefficient of Curvature CC = (D30)2 / (D60 × D10) = .
CONCLUSION:
Particle Type %
Silt and Clay
Sand
Gravel
Types of Soil
7 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 2. A
ATTERBERG LIMITS OF FINE-GRAINED SOIL
LIQUID LIMIT BY CASAGRANDE METHOD (IS: 2720 Part 5)
OBJECTIVE:
To determination liquid limit of given soil sample by Casagrande method.
NEED AND SCOPE:
Liquid limit is significant to know the stress history and general properties of the soil
met with construction. From the results of liquid limit the compression index may be
estimated. The compression index value will help us in settlement analysis. If the
natural moisture content of soil is closer to liquid limit, the soil can be considered as
soft if the moisture content is lesser than liquids limit, the soil can be considered as soft
if the moisture content is lesser than liquid limit. The soil is brittle and stiffer.
APPARATUS:
Mechanical Liquid Limit Device - It shall conform to IS: 9259-1979.
Grooving Too-It shall conform to IS: 9259- 1979.
Porcelain Evaporating Dish - about 12 to 15 cm in diameter.
Flat Glass Plate-10 mm thick and about 45 cm square or larger (alternative to
porcelain evaporating dish for mixing soil with water).
Spatula-flexible, with the blade about 8 cm long and 2 cm wide (for mixing soil and
water in the porcelain evaporating dish).
Palette Knives-two, with the blade about 20 cm long and 3 cm wide (for mixing soil
and water on the flat glass plate).
Balance-sensitive to 0.01 g.
Oven-thermostatically controlled with interior of non-corroding material to maintain
the temperature between 105 and 110°C.
Wash Bottle or Beaker-containing distilled water containers-air-tight and non-
corrodible for determination of moisture content.
8 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Apparatuses and filling sample in cup
Groove in Soil Sample
SOIL SAMPLE:
A sample weighing about 120 g shall be taken from the thoroughly mixed portion of
material passing 425- micron IS Sieve is IS: 460 (Part I)-19781 obtained in
accordance with IS: 2720 (Part I)-1983.
9 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
PROCEDURE:
About 120 g of the soil sample passing 425-micron IS Sieve shall be mixed thoroughly
with distilled water in the evaporating dish or on the flat glass to form a uniform paste.
The paste shall have a consistency that will require 30 to 35 drops of the cup to cause
the required closure of the standard groove. In the case of clayey soils, the soil paste
shall be left to stand for a sufficient time (24 hours) so as to ensure uniform distribution
of moisture throughout the soil mass.
The soil should then be re-mixed thoroughly before the test. A portion of the paste shall
be placed in the cup above the spot where the cup rests on the base, squeezed down and
spread into position, with as few strokes of the spatula as possible and at the same time
trimmed.
A depth of 1 cm at the point of maximum thickness, returning the excess soil to the
dish. The soil in the cup shall be decided by firm strokes of the grooving tool along the
diameter through the center line of the cam follower so that a clean, sharp groove of the
proper dimensions is formed.
The cup shall be fitted and dropped by turning the crank at the rate of two revolutions
per second until the two halves of the soil cake come in contact with bottom of the
groove along. A distance of about 12 mm. This length shall be measured with ‘the end
of the grooving tool or a ruler. The number of drops required to cause the grove close
for the length of 12 mm shall be recorded. A little extra of the soil mixture shall be
added to the cup and mixed with the soil in the cup. The pat shall be made in the cup
and the test repeated.
In no case shall dried soil be added to the thoroughly mixed soil that is being tested and
in, this clause shall be repeated until two consecutive runs give the same under of drops
for closure of the groove.
A representative slice of soil approximately the width of the spatula, extending from
about edge to edge of the soil cake at right angle to the groove and including that portion
of the groove in which the soil flowed together. Shall be taken in a suitable container
and its moisture content expressed as a percentage of the oven-dry weight otherwise
determined as described in IS: 2720 (Part 2)-1973. The remaining soil in the cup shall
10 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
be transferred to the evaporating dish and the cup and the grooving tool cleaned
thoroughly.
The operations shall be repeated for at least three more additional trials (minimum of
four in all), with the soil collected in the evaporating dish or flat glass plate, to which
sufficient water has been added to bring the soil to a more fluid condition. In each case,
the number of blows shall be recorded and the moisture content determined as before.
The specimens shall be of such consistency that the number of drops required to close
the groove shall be not less than 15 or not more than 35 and the points on the flow curve
are evenly distributed in this range. The test should proceed from the drier (more drops)
to the wetter (less drops) condition of the soil. The test may also be conducted from the
wetter to the drier condition provided drying is achieved by kneading the wet soil and
not by adding dry soil.
LIQUID LIMIT (WL):
A flow curve shall be plotted on semi-logarithmic graph representing water content on
the arithmetical scale and the number of drops on the logarithmic scale. The flow curve
is a straight line drawn as nearly as possible through the four or more plotted points.
The moisture content corresponding to 25 drops as read from the curve shall be rounded
off to the nearest whole number and reported as the liquid limit of the soil.
OBSERVATION TABLE:
Sample 1 2 3 4 5
Number of drop
Container number
Container Weight
Weight of cont. + wet soil, g
Weight of cont. +oven dry soil, gm
Weight of water
Weight of oven dry sample
Moisture content
11 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Liquid limit of given soil sample(WL) = %
CONCLUSION:
12 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 2. B
PLASTIC LIMIT TEST (IS: 2720 Part 5)
OBJECTIVE:
To determine the plastic limit of the soil sample and to calculate plasticity index,
Toughness index of fine-grained soil.
APPARATUS:
Porcelain Evaporating Dish about 12 cm in diameter.
Flat Glass Plate - 10 mm thick and about 45 cm square or larger.
Spatula - flexible, with the blade about 8 cm long and 2 cm wide. Or Palate Knives-
two, with the blade about 20cm long and 3 cm wide (for use with flat glass plate for
mixing soil and water).
Surface for Rolling - ground-glass plate 20 × 15cm. Containers - air-tight to determine
moisture content.
Balance - sensitive to 0.01 g.
Oven - thermostatically controlled with interior of no corroding material to maintain
the temperature between 105 and 110 ̊ C.
Rod-3 mm in diameter and about 110 cm long.
SOIL SAMPLE
A sample weighing about 20 g from the thoroughly mixed portion of the material
passing 425-micron IS Sieve, obtained in accordance with IS -2720 (Part l)-1983 shall
be taken
13 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
PROCEDURE
1. Use the remaining (from liquid limit) soil from the porcelain dish.
2. Take about 10 gm of the soil mass in the hand, form a ball, and roll it between the palm
or the fingers and the glass plate using complete motion of the hand forward and
reverse.
3. Apply only sufficient pressure to make a soil thread, and continue rolling until a thread
of 3 mm diameter is formed. Comparison can be made with the metal rod.
4. If the diameter becomes less than 3 mm without cracking, turn the soil into a ball again,
and re-roll. Repeat this remoulding and rolling process until the thread starts just
crumbling at a diameter of 3 mm.
5. Gather the pieces of crumbled thread and place them in a moisture can for determining
water content.
6. Repeat steps 2 to 5 at least two more times with fresh samples of 10 gm each.
Process of Plastic Limit Test
14 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
OBSERVATION TABLE:
SUMMARY
Liquid
limit
WL
Flow
Index
IF
Plasti
c
limit
Wp
Plasticit
y index
IP=WL-
WP
Toughnes
s index
It=IP/IF
Liquidity
index
IL=(W-
WP)/IP
Consistency
index
IC=(WL-
W)/IP
CONCLUSION:
Plastic limit
Sample 1 2 3 4 5
Container number
Container Weight
Weight of cont. + wet soil, g
Weight of cont. +oven dry soil, g
Weight of water
Weight of oven dry sample
Moisture content
15 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 2. C
SHRINKAGE LIMIT (IS: 2720 Part- 6)
OBJECTIVE:
To determine the shrinkage limit and calculate the shrinkage ratio for the given soil.
NEED AND SCOPE
Soils which undergo large volume changes with change in water content may be
troublesome. Volume changes may not and usually will not be equal.
To obtain a quantitative indication of how much change in moisture can occur before
any appreciable volume changes occurs
To obtain an indication of change in volume.
The shrinkage limit is useful in areas where soils undergo large volume changes when
going through wet and dry cycles (as in case of earth dams)
APPARATUS:
Evaporating Dish. Porcelain, about 12cm diameter with flat bottom.
Spatula
Shrinkage Dish. Circular, porcelain or non-corroding metal dish (3 nos) having a flat
bottom and 45 mm in diameter and 15 mm in height internally.
Straight Edge. Steel, 15 cmm in length.
Glass cup. 50 to 55 mm in diameter and 25 mm in height, the top rim of which is ground
smooth and level.
Glass plates. Two, each 75 75 mm one plate shall be of plain glass and the other shall
have prongs.
Sieves 2mm and 425- micron IS sieves.
Oven-thermostatically controlled.
Graduate-Glass, having a capacity of 25 ml and graduated to 0.2 ml and 100 cc one
mark flask.
Balance-Sensitive to 0.01 g minimum.
16 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Mercury. Clean, sufficient to fill the glass cup to over flowing 12.Wash bottle
containing distilled water.
Apparatuses of Shrinkage limit
PROCEDURE
Preparation of soil paste
Take about 100 gm of soil sample from a thoroughly mixed portion of the material
passing through 425-micron I.S. sieve.
Place about 30 gm the above soil sample in the evaporating dish and thoroughly mixed
with distilled water and make a creamy paste.
Use water content somewhere around the liquid limit.
Filling the shrinkage dish
Coat the inside of the shrinkage dish with a thin layer of Vaseline to prevent the soil
sticking to the dish.
Fill the dish in three layers by placing approximately 1/3 rd of the amount of wet soil
with the help of spatula. Tap the dish gently on a firm base until the soil flows over the
edges and no apparent air bubbles exist. Repeat this process for 2nd and 3rd layers also
17 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
till the dish is completely filled with the wet soil. Strike off the excess soil and make
the top of the dish smooth. Wipe off all the soil adhering to the outside of the dish.
Weigh immediately, the dish with wet soil and record the weight.
Air- dry the wet soil cake for 6 to 8hrs, until the colour of the pat turns from dark to
light. Then oven- dry the to constant weight at 105˚C to 110˚C say about 12 to 16 hrs.
Remove the dried disk of the soil from oven. Cool it in a desiccators. Then obtain the
weight of the dish with dry sample.
Determine the weight of the empty dish and record.
Determine the volume of shrinkage dish which is evidently equal to volume of the wet
soil as follows. Place the shrinkage dish in an evaporating dish and fill the dish with
mercury till it overflows slightly. Press it with plain glass plate firmly on its top to
remove excess mercury. Pour the mercury from the shrinkage dish into a measuring jar
and find the volume of the shrinkage dish directly. Record this volume as the volume
of the wet soil pat.
Volume of the Dry Soil Pat
Determine the volume of dry soil pat by removing the pat from the shrinkage dish and
immersing it in the glass cup full of mercury in the following manner.
Place the glass cup in a larger one and fill the glass cup to overflowing with mercury.
Remove the excess mercury by covering the cup with glass plate with prongs and
pressing it. See that no air bubbles are entrapped. Wipe out the outside of the glass cup
to remove the adhering mercury. Then, place it in another larger dish, which is, clean
and empty carefully.
Place the dry soil pat on the mercury. It floats submerge it with the pronged glass plate
which is again made flush with top of the cup. The mercury spills over into the larger
plate. Pour the mercury that is displayed by the soil pat into the measuring jar and find
the volume of the soil pat directly.
18 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
CALCULATION
First determine moisture contain
Shrinkage Limit 𝑊𝑆 = (𝑊 – (𝑉 − 𝑉0) ∗ (𝛾𝑤
𝑊0))
o Where, W = Moisture content of pat (%)
o V = Volume of wet soil pat in cm3
o V0 = Volume of dry soil pat in cm3
o W0 = Weight of even dry soil pat in gm
Caution
Do not touch the mercury with gold rings.
Observation sheet for shrinkage limit
Sr.
No Determination No. 1 2 3
1 Wt. of container in g W1
2 Wt. of container +wet of soil pet in g (W2)
3 Wt. of container +dry of soil pat in g (W2)
4 Wt. of oven dry soil pat in g (W0)
5 Wt. of water
6 Moisture content (W %)
7 Volume of wet soil pat in cm3
8
Volume of
dry soil pat
in cm3
By Mercury
displacemen
t method
a. Weight of
displaced
Mercury
b. Specific gravity
of Mercury
9 Shrinkage limit(Ws)
10 Shrinkage Ratio (R)
19 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
CONCLUSION:
20 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 3. A
IN - SITU DENSITY BY CORE CUTTER METHOD (IS: 2720 Part- 29)
OBJECTIVE:
To determine in - situ density by core cutter method.
APPARATUS:
Cylindrical core cutter
Dolly, Rammer
Balance (1 g accuracy)
Spade
Straight edge knife
Sample extruder
Apparatus for moisture content determination
21 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
PROCEDURE
Measure the internal dimensions of the core cutter and weigh it.
Clean and level the site surface where the field density is to be determined.
Place the dolly on the cutter and press both into the soil using the rammer until only
about 15 mm of the dolly protrudes above the surrounding soil surface.
Remove the soil around the cutter with the spade, lift up the cutter, and trim carefully
the top and bottom surfaces of the soil sample.
Clean the outside surface of the cutter and weigh it with the soil.
Remove the soil core from the cutter and take three representative samples in
moisture cans for water content determination.
OBSERVATIONS:
Internal diameter of core cutter, (cm) =
Height of cutter, (cm) =
Volume of cutter, V (cm3) =
Test No. 1 2 3
Mass of core cutter (g), W1
Mass of cutter + soil (g), W2
Mass of moist soil (g), (W2- W1)
Average water content, W (%)
Field bulk density (g/cm3),
Field dry density (g/cm3),
In-situ dry density (Average of the computed
values)
22 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
CONCLUSION:
23 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 3. B
IN – SITU DENSITY BY SAND REPLACEMENT METHOD
(IS: 2720 Part- 28)
OBJECTIVE:
To determine in – situ density of field by sand replacement method.
NEED AND SCOPE:
The in situ density of natural soil is needed for the determination of bearing capacity of
soils, for the purpose of stability analysis of slopes, for the determination of pressures
on underlying strata for the calculation of settlement and the design of underground
structures
APPARATUS:
Sand pouring cylinder
Calibrating cylinder
Clean and dry sand
Metal tray with a central circular hole
Balance (1 gm accuracy)
Glass plate, Trowel, Scraper tool
Apparatus for moisture content determination.
24 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
PROCEDURE:
An inverted cone forms the base of the sand pouring cylinder, and a shutter at the cone
tip controls the release of sand through a uniform free fall.
First determine the bulk density of the sand to be used in the field. For this, measure the
internal dimensions of the calibrating cylinder so as to obtain its volume. Fill the
pouring cylinder with sand and weigh. Place it concentrically on top of the calibrating
cylinder, and allow sand to run out and fill both the calibrating cylinder and the inverted
conical portion.
To obtain only the mass of sand filling up the conical portion, lift the pouring cylinder
and then weigh with remaining sand. Place it on a glass plate, and allow sand to run
out. Weigh again the pouring cylinder with left over sand.
Calculate the mass of sand that fills up the calibrating cylinder, and from its known
volume, work out the bulk density of the sand for the allowed free fall.
Clean and level the site surface, and place the square tray with a central hole. Excavate
a hole of diameter equal to that of the tray hole and depth equal to about 15 cm. Collect
the excavated soil in the tray, weigh and then take representative samples for water
content determination.
Fill the pouring cylinder with the same sand, place it concentrically over the hole, open
the shutter and allow sand to fill up the hole.
When there is no further movement of sand, close the shutter, remove the cylinder and
weigh it with the remaining sand.
25 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
OBSERVATIONS:
Bulk density of sand, = (g/cm3)
Volume of calibrating cylinder, V1 = (cm3)
Mass of sand for filling the calibrating cylinder and cone W1 = (gm)
Mass of sand for filling only the cone, W2 = (gm),
Mass of sand in the calibrating cylinder (g), W3 = W1 – W2 = (gm),
CONCLUSION:
Field Test No.
1
2
3
Mass of pouring cylinder + sand before pouring in
hole (g), W4
Mass of pouring cylinder + sand after pouring in
hole (g), W5
Mass of sand used in the hole (g), W6 = W4 - W5 -
W2
Volume of excavated hole (cm3),
Mass of excavated soil (g), W
Average water content, w (%)
Field bulk density (g/cm3)
Field dry density (g/cm3)
Avg. Field Density
26 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 4. A
CONSTANT HEAD PERMEABILITY TEST (IS: 2720 Part- 17)
OBJECTIVE:
To determine the coefficient of permeability of a soil using constant head apparatus
NEED AND SCOPE:
The knowledge of this property is much useful in solving problems involving yield of
water bearing strata, seepage through earthen dams, stability of earthen dams, and
embankments of canal bank affected by seepage, settlement etc
APPARATUS:
Permeameter mould and accessories
Circular filter papers, Compaction device
Constant head reservoir
Measuring flask
Stop-watch
Test Setup Diagrame of Test Process
27 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Mouls Section Coller Elevation Section Bottom Secion of
mould
PROCEDURE:
Take 2.5 kg of dry soil and prepare it to obtain desired water content.
Apply little grease on to the interior sides of the permeameter mould.
Keep a solid metal plate in the groove of the compaction base plate. Assemble the
base plate, mould and collar. Compact the soil into the mould.
Remove the collar and base plate, and replace the solid metal plate with a porous
stone covered with filter paper.
Trim off excess soil from the top of the mould and place another porous stone with
filter paper on it. Attach the top cap of the permeameter.
Connect a constant head reservoir to the bottom outlet of the mould. Open the air
vent of the top cap, and allow water to flow in and upwards till the soil gets saturated.
Disconnect the reservoir from the bottom outlet and connect it to the top inlet. Close
the air vent and allow water to establish a steady flow.
Collect the water in a measuring flask for a convenient time interval. For similar
time intervals, measure the flow quantity for at least three times.
After the test, measure the temperature of the water.
28 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
OBSERVATION:
Diameter of sample D (cm) =
Length of sample L (cm) =
Area of sample A (cm2) =
Volume of sample V (cm3) =
Initial mass of sample W (g) =
Initial water content w (%) =
Moulding density (g/cm3) =
Sr.
No
Quantity of
water
collected
(Q) ml
Duration
(t)
secon
d
Constant
head h
(cm)
i = h / L
𝑲 = (𝑸 ∗ 𝑳
𝒕 ∗ 𝒉 ∗ 𝑨)
1
2
3
AVG. Permeability k
CONCLUSION:
29 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 4. B
FALLING HEAD PERMEABILITY TEST (IS: 2720 Part- 4)
OBJECTIVE:
To determine coefficient of permeability of a soil using falling head / variable head
apparatus
NEED AND SCOPE
To estimate ground water flow, to calculate seepage through dams, to find out the rate
of consolidation and settlement of structures, to plan the method of lowering the ground
water table, to calculate the uplift pressure and piping, to design the grouting, And also
for soil freezing tests, to design pits for recharging.
APPARATUS:
Permeameter mould and accessories
Circular filter papers, Compaction device
Graduated glass standpipes along with support frame and clamps
Measuring flask
Stop-watch.
30 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Test Setup
PROCEDURE:
Follow the same steps 1 to 6 as for the constant head test.
Disconnect the reservoir from the bottom outlet and connect a selected standpipe to
the top inlet.
Fill the standpipe with water, close the air vent and allow water to flow.
Open the bottom outlet and record the time interval required for the water surface in
the standpipe to fall between two levels as measured from the centre of the outlet.
Measure time intervals for similar drops in head at least three times after re-filling the
standpipe.
At the end of the test, measure the temperature of the water.
31 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
OBSERVATION TABLE:
Diameter of standpipe, d = (cm)
Cross-sectional area of standpipe, a = (cm2)
Test No. 1 2 3
Initial head, h1 (cm)
Final head , h2 (cm)
Time interval in seconds, ( t2 - t1)
Avg. Coefficient of permeability (cm/sec)
CONCLUSION:
32 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
EXPERIMENT: 5.
LIGHT & HEAVY PROCTOR COMPACTION TEST
(IS: 2720 Part- 7 & 8)
OBJECTIVE:
To determine the relation between the water content and the dry density of soils using
light/heavy proctor compaction.
APPARATUS:
SampleExtruder (Optional)
Container, Tray or pan, Trowel and spatula, Spoon, Oven, Mould
Balances- capacity of 10 kg and 1 gm sensitive & other of capacity 200 gm and 0.01
gm sensitive
Steel Straightedge - Mixing Tools, Metal Rammer,
PROCEDURE FOR LIGHT COMPACTION:
Obtain a sufficient quantity of air-dried soil and pulverize it. Take about 5 kg of soil
passing through 19 mm sieve in a mixing tray.
Weigh the mould with base plate and apply grease lightly on the interior surfaces. Fit
the collar and place the mould on a solid base.
Add water to the soil to bring its moisture content to about 8% and then mix it
thoroughly using the trowel until the soil gets a uniform color.
For light compaction, compact the moist soil in three equal layers using a rammer of
mass 2.6 kg and having free fall of 31 cm. Distribute the blows evenly, and apply 25
blows in each layer. Ensure that the last compacted layer extends above the collar joint.
Alternatively for heavy compaction, compact the soil with 25 blows per layer, in five
equal layers with a rammer of mass 4.9 kg and 45 cm free fall.
Rotate the collar so as to remove it, trim off the compacted soil flush with the top of the
mould, and weigh the mould with soil and base plate.
33 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
Extrude the soil from the mould and collect soil samples from the top, middle and
bottom parts for water content determination. Place the soil back in the tray, add 2%
more water based on the original soil mass, and re-mix as in step 3. Repeat steps 4 and
5 until a peak value of compacted soil mass is reached followed by a few samples of
lesser compacted soil masses.
Calculate the bulk density of each compacted soil specimen.
Calculate the average moisture content of the compacted specimen and then its dry
density.
Plot the dry densities obtained as ordinates against the corresponding moisture contents
as abscissa, draw a smooth compaction curve passing through them, and obtain the
values of maximum dry density (MDD) and optimum moisture content (OMC).
On the same graph, plot a curve corresponding to 100% saturation, calculated from
Where, S = degree of saturation,
Gs = specific gravity of solids,
Ƴw = unit weight of water.
CALCULATIONS:
Bulk Density –γb in g/cc, of each compacted specimen shall be calculated from the
equation:
𝛾𝑏 = ( 𝑀2− 𝑀1
𝑉𝑀)
Where, M1= mass in g of mould and base
M2 = mass in g of mould, base and soil; and
VM = volume in cm3 of mould.
34 Darshan Institute of Engineering & Technology, Rajkot
DEPARTMENT OF CIVIL ENGINEERING
3130606- GEOTECHNICAL ENGINEERING LAB MANUAL
The dry density, γd in g/cc, shall be calculated from the equation:
𝛾𝑑 = (𝛾𝑏
1 + 𝑤/100)
Where, γb = builk density
w = water content of soil (%)
OBSERVATION:
CONCLUSION:
Type of test (Standard/ Modified proctor test)
Volume of mould (cm3) (1000cm3/2250cm3)
No .of Test 1 2 3 4 5
Container no.
Empty weight of container
Container + wet soil(gm)
Container+ dry soil (gm)
Mass of mould (gm)
Mass of mould + compacted soil (gm)
Mass of compacted soil, Wt.(gm)
Bulk density (g/cc)
Average water content w (%)
Dry density (g/cc )
Dry density at 100% saturation (g/cc )
RESULT SUMMARY (after plotting a graph)
Maximum Dry Density… ....................... gm/cc