SOIL MOISTURE ANALYSIS

SOIL MECHANICS LAB MANUAL G.Hussain Gorchani
1
JOB NO: 1
MOISTURE CONTENT OF SOIL SAMPLE
BY OVEN DRIVED METHOD
OBJECTIVE:
To determine the moisture content by using oven dried method.
SCOPE & SIGNIFICANCE:
For many soil sample, the water content is very important, used for relationship between the soil behaves & its property
the consistency of fine grained soil largely depend on its water content. The water content is also used in expressing the
phase relationship of air, water & solid in a given volume.
DEFINITION:
It is the ratio of weight of water to the weight of solids in a given mass of soil. This ratio is usually expressed in %age.
W=
PRINCIPLE:
The method is based on the removing soil moisture by oven drayed sample until the weight remains same. The moisture
content is calculated (%) from sample weight before & after drying.
APPARATUS:
 Drying oven
 Balance (readable accurate to 0.01 Gramm)
 Can (aluminums tins with close fitting numbered lids diameter 75mm & 25mm deep)
 Spatula
PRECAUTIONS:
 Some dried material may absorb moisture content from the moist specimen. The dried specimen should be
removed before placing new wet soil sample in the oven.
 Cover the container lid if you are taking the sample form a reasonable distance from the lab.
 To assist the oven drying of large test samples, It is advisable to use containers having large surface area and
breakup the material into smaller aggregates.
 If it is suspected that gypsum is present in the soil. Sample should not be subjected to the temperature beyond 80o
C, otherwise gypsum would lose its water of crystallization, affecting the result of moisture content. Oven drying
at 80oC may, however, be continued for a longer time in order to ensure the complete evaporation of free water
present in the soil sample.

2
PROCEDURE:
 Take 3 can. Record mass of can & led no. Determine its empty weight & record it clean dry can & lid
 Dig up a whole up to 1’ from where you have to test the soil sample & take soil sample in can & weight it.
 Then dig the whole to more depth up to 2’.take soil sample in 2nd
can & record its weight.
 Then dig the whole up to 3’ take sample and weight it.
 Then place the sample in oven & set the oven temperature & leave for 24 hours
 Remove the can carefully replace the lid &allow it to cool to room temperature
 Determine and record the mass of can
DATA ANALYSIS:
W1= weight of can with lid
W2= weight of moist soil +lid
W3= weight of dried soiled + can
Determination of mass of soil mass => M soil = w3-w1
Determination of mass of water => Ww = w2-w3
Moisture content: => M/c = Ww / Ws x 100
OBSERVATION & CALCULATIONS:
TABLE:1
Group #.
Depth
(ft.)
Cane #.
W1
(Wt. of cane)
W2
(Wt. of cane + wt.
of wet soil)
W3
(Wt. of cane + dry soil)
Moisture
Content
W (%age)
01
1’ 09 37.6g. 151.6469g 146.6239g 4.61
2’ 10 37.2g 142.7274g 137.3872g 5.33
3’ 11 32.6g 149.5303g 135.3463g 13.8
02
1’ 01 33,7g 115.803g 111.3293g 5.76
2’ 03 36.1g 125.278g 120.4061g 5.78
3’ 05 38.0g 151.022g 139.0246g 11.88
03
1’ 04 33.9g 128.087g 122.8321g 5.91
2’ 07 33.7g 122.1699g 115.3627g 8.34
3’ 08 37.5g 128.4710g 119.437g 11.03
COMMENTS:

3
JOB NO:2
LIQUID LIMIT OF SOIL SAMPLE
OBJECTIVE:
This lab is performed to determine the liquid limits of a fine-grained soil.
STANDARD REFERENCE:
ASTM D 4318 - Standard Test Method for Liquid Limit.
RELATED THEORY:
Liquid limit:
Liquid limit is defined as the arbitrary limit of water content at which the soil is just about to pass from the plastic state
into the liquid state. At this limit, the soil possesses a small value of shear strength, losing its ability to flow as a liquid In
other words the liquid limit is the minimum moisture content at which the soil tends to flow as a liquid.
Liquidity index:
Liquidity index (LI OR IL) or Water-plasticity ratio ‘is the ratio of the difference between the natural water content and
the plastic limit to the plasticity index, the soil is in liquid state. < 0, the soil is in semi-solid state and is stiff. Obviously
CI + LI = 1
APPARATUS:
 Liquid limit device
 Porcelain (evaporating) dish
 Flat grooving tool with gage
 Eight moisture cans
 Balance
 Glass plate
 Spatula
 Wash bottle filled with distilled water
 Drying oven
REQUIREMENTS:
 Soil sample must pass through ASTM Sieve#40 (0.425 mm).
 The sample should be air dried.
APPLICATIONS:
 To obtain the general information about the soil strength, compressibility,
 Permeability and shrink and swell properties.
 To estimate the consolidation settlement.
 For soil classification.
 Construction specifications

4
PRECAUTIONS:
The test should always proceed from drier to wetter condition if it should occur that too much water added to the soil, it is
difficult to that dry the soil by adding the additional dry soil.
PROCEDURE:
 Take roughly 3/4 of the soil and place it into the porcelain dish. Assume that the soil was previously passed
through a No40 sieve air dried and then pulverized. Thoroughly mix the soil with a small amount of distilled
water until it appears as a smooth uniform paste. Cover the dish with cellophane to prevent moisture from
escaping.
 Weigh four of the empty moisture cans with their lids, and record the respective weights and can numbers on the
data sheet.
 Adjust the liquid limit apparatus by checking the height of drop of the cup. The point on the cup that comes in
contact with the base should rise to a height of 10 mm. The block on the end of the grooving tool is Engineering
Properties of Soils Based on Laboratory Testing 10 mm high and should be used as a gage. Practice using the cup
and determine the correct rate to rotate the crank so that the cup drops approximately two times per second.
 Place a portion of the previously mixed soil into the cup of the liquid limit apparatus at the point where the cup
rests on the base. Squeeze the soil down to eliminate air pockets and spread it into the cup to a depth of about 10
mm at its deepest point. The soil pat should form an approximately horizontal surface (See Photo B).
 Use the grooving tool carefully cut a clean straight groove down the center of the cup. The tool should remain
perpendicular to the surface of the cup as groove is being made. Use extreme care to prevent
 Make sure that the base of the apparatus below the cup and the underside of the cup is clean of soil. Turn the
crank of the apparatus at a rate of approximately two drops per second and count the number of drops, N, it takes
to make the two halves of the soil pat come into contact at the bottom of the groove along a distance of 13 mm
(1/2 in.) (See Photo D). If the number of drops exceeds 50, then go directly to step eight and do not record the
number of drops, otherwise, record the number of drops on the data sheet.
 Take a sample, using the spatula, from edge to edge other soil pat. The sample should include the soil on both
sides of where the groove came into contact. Place the soil into a moisture can cover it.
 Immediately weigh the moisture can containing the soil, record it’s Engineering Properties of Soils Based on
Laboratory Testing mass, remove the lid, and place the can into the oven. Leave the moisture can in the oven for
at least 16 hours. Place the soil remaining in the cup into the porcelain dish. Clean and dry the cup on the
apparatus and the grooving tool.
 Remix the entire soil specimen in the porcelain dish. Add a small amount of distilled water to increase the water
content so that the number of drops required closing the groove decrease.
 Repeat steps six, seven, and eight for at least two additional trials producing successively lower numbers of drops
to close the groove. One of the trials shall be for a closure requiring 25 to 35 drops, one for closure between 20
and 30 drops, and one trial for a closure requiring 15 to 25 drops. Determine the water content from each trial by
using the same method used in the first laboratory. Remember to use the same balance for all weighing.

5
CALCULATION & OBSERVATION:
TABLE:2
GRAPH:2
Liquid Limit = 20.41%
Comments:

6
JOB NO: 03
PLASTIC LIMIT OF SOIL
OBJECTIVE:
This lab is performed to determine the plastic limit of a fine-grained soil.
STANDARD REFERENCE:
ASTM D 4318 - Standard Test Method for Plastic Limit.
RELATED THEORY:
Plastic limit:
The plastic limit (PL) is the water content where soil starts to exhibit plastic behavior. A thread of soil is at its plastic limit
when it is rolled to a diameter of 3mm or begins to crumble. To improve consistency, a 3mm diameter rod is often
used to gauge the thickness of the thread when conducting the test.
Plasticity Index:
Plasticity index‘(PI or) is the range of water content within which the soil exhibits plastic properties; that is, it is the
difference between liquid and plastic limits. I (or) = (LL - PL) When the plastic limit cannot be determined, the material is
said to be non-plastic (NP).Plasticity index for sands is zero. For proper evaluation of the plasticity properties of a soil, it
has been found desirable toques both the liquid limit and the plasticity index values.
APPARATUS:
 Balance
 Glass plate
 Spatula
 Drying oven
REQUIREMENTS:
APPLICATIONS:

7
PRECAUTIONS:
PROCEDURE:
 Weigh the remaining empty moisture cans with their lids, and record the respective weights and can numbers on
the data sheet.
 Take the remaining 1/4 of the original soil sample and add distilled Water until the soil is at a consistency where it
can be rolled without sticking to the hands.
 Form the soil into an ellipsoidal mass (See Photo F). Roll the mass between the palm or the fingers and the glass
plate (See Photo G). Use sufficient pressure to roll the mass into a thread of uniform Engineering Properties of
Soils Based on Laboratory Testing diameter by using about 90 strokes per minute. (Stroke is one complete motion
of the hand forward and back to the starting position.) The thread shall be deformed so that its diameter reaches
3.2 mm (1/8 in.), taking no more than two minutes.
 When the diameter other thread reaches the correct diameter, break the thread into several pieces. Knead and
reform the pieces into ellipsoidal masses and re-roll them. Continue this alternate rolling, gathering together,
kneading and re-rolling until the thread crumbles under the pressure required for rolling and can no longer be
rolled into a 3.2 mm diameter thread (See Photo H).
 Gather the portions of the crumbled thread together and place the soil into a moisture can, then cover it. If the can
does not contain at least 6 grams of soil, add soil to the can from the next trial (See Step 6). Immediately weigh
the moisture can containing the soil, record it’s mass, remove the lid, and place the can into the oven. Leave the
moisture can in the oven for at least 16 hours.
 Repeat steps three, four, and five at least two more times. Determine the water content from each trial by using
the same method used in the first laboratory. Remember to use the same balance for all weighing. Engineering
Properties of Soils Based on Laboratory Testing.
DIAGREM

8
Fig.3a: Apparatus for plastic limit test
OBSERVATIONS & CALCULATIONS:
Table 3
Can # Empty wt. Wet Soil + Can Dry Soil + Can Wt. of Water Wt. of Dry Soil M.C
6 38.9 40.98 40.7 0.28 1.8 15.56%
1 33.7 36.05 35.7 0.35 2 17.50%
4 33.7 38.95 38.2 0.75 4.5 16.67%
COMMENTS:

9
JOB NO: 04
SHRINKAGE LIMIT OF SOIL
OBJECTIVE:
This lab is performed to determine the shrinkage limit of a fine-grained soil.
STANDARD REFERENCE:
ASTM D 4318 - Standard Test Method for Shrinkage limit.
RELATED THEORY:
Shrinkage limit:
The shrinkage limit (SL) is the water content where further loss of moisture will not result in any more volume reduction.
The shrinkage limit is much less commonly used than the liquid limit and the plastic limit.
Shrinkage Index:
Shrinkage index is defined as the difference between the plastic and shrinkage limits of a soil; in other words, it is the
range of water content within which a soil is in a semisolid state of consistency.
APPARATUS:
 Balance
 Glass plate
 Spatula
 Drying oven
REQUIREMENTS:
APPLICATIONS:

10
PRECAUTIONS:
PROCEDURE:
1. Put about 80 to 100 grams of a representative air dry soil, passed through No. 40 sieve, into an evaporating dish
2. Add water to the soil from the plastic squeeze bottle and mix it thoroughly into the form of a creamy paste Note
that the moisture content of the paste should be above the liquid limit of the soil to ensure full saturation
3. Coat the shrinkage limit dish lightly with petroleum jelly and then determine the mass of the coated dish (WI) in
grams.
4. Fill the dish about one-third full with the soil paste. Tap the dish on a firm surface so that the soil flows to the
edges of the dish and no air bubbles exist.
5. Repeat Step 4 until the dish is full.
6. Level the surface of the soil with the steel straight edge. Clean the sides and bottom of the dish with paper
towels.
7. Detennine the mass of the dish plus the wet soil (W2) in grams.
8. Allow the dish to air dry (about 6 hours) until the color of the soil pat becomes lighter. Then put the dish with
the soil into the oven to dry.
9. Determine the mass of the dish and the oven-dry soil pat (W3) in grams.
10. Remove the soil pat from the dish
11. In order to find the volume of the shrinkage limit dish (Vi), fill the dish with mercury. (Note: The dish should be
placed on a watch glass.) Use the three-pronged glass plate and level the surface of the mercury iIi the dish. The
excess mercury will flow into the watch glass. Determine the mass of mercury in the dish (W4) in grams
12. In order to determine the volume of the dry soil pat (VI)' fill the glass cup with mercury. (The cup should be
placed on a watch glass.) Using the three-pronged glass plate, level the surface of the mercury in the glass cup.
Remove the excess mercury on the watch glass. Place the dry soil pat on the mercury in the glass cup. The soil
pat will float. Now, using the three-pronged glass plate, slowly push the soil pat into the mercury until the soil
pat is completely submerged (Fig. 8-3). The displaced mercury will flow out of the glass cup and will be collected
on the watch glass. Determine the mass of the displaced mercury on the watch glass (Ws) in grams.

11
Fig4a Determination of the volume of the soil pat
CALCULATION:
1. Calculate the initial moisture content of the soil at molding.
2. Calculate the change in moisture content (%) before the volume reduction ceased
where Pw ~ density of water = 1 g/c
3. Calculate the shrinkage limit.
Note that and are in grams and the specific gravity of the mercury is 13.6. A sample calculation is shown in
TABLE:4
TEST NO /
Mass of coated shrinkage limit dish w (g) 12.34
Mass of dish + wet soil w (g) 40.43
Mass of dish + dry soil w (g) 33.68
31.63
Mass of mercury to fill the dish w (g) 198.83
Mass of mercury displaced by soil pat w (g) 150.30
16.72
14.91
COMMENTS:

12
JOB NO: 05
DETERMINATION OF SPECIFIC GRAVITY
PURPOSE:
This lab is performed to determine the specific gravity of soil by using a pycno meter. Specific gravity is the ratio of the
mass of unit volume of soil at a stated temperature to the mass of the same volume of gas-free distilled water at a stated
temperature.
STANDARD REFERENCE:
ASTM D 854-00 Standard Test for Specific Gravity of Soil Solids by Water Pycnometer.
SCOPE & SIGNIFICATION:
o Specific gravity is required in the calculation associated in the grain size consolidation & compaction.
o At as also used to solve various phase relationship such that void ratio, porosity, & degree of saturation etc
o The knowledge of specific gravity is needed in calculation of soil properties like void ratio, degree of saturation
etc.
DEFINITION:
Specific gravity G is defined as the ratio of the weight of material to unite weight of of distilled water at 4 co.
APPARATUS REQUIRED:
1. Density bottle of 50 ml with stopper having capillary hole.
2. Balance to weigh the materials (accuracy 0.01gm).
3. Wash bottle with distilled water.
4. Alcohol and ether.

13
Fig.5a: Apparatus for determination of specific gravity
PROCEDURE:
1) Clean and dry the density bottle
a) wash the bottle with water and allow it to drain.
b) Wash it with alcohol and drain it to remove water.
c) Wash it with ether, to remove alcohol and drain ether.
2)Weigh the empty bottle with stopper (W1)
3) Take about 10 to 20 gm of oven soil sample which is cooled in a desiccator.
4) Transfer it to the bottle. Find the weight of the bottle and soil (W2).
5) Out 10ml of distilled water in the bottle to allow the soil to soak completely Leave it for about 2 hours
6) Again fill the bottle completely with distilled water put the stopper and keep the bottle under constant
temperature water baths (Tx0 ).
7) Take the bottle outside and wipe it clean and dry note. Now determine the weight of the bottle and the contents
(W3).
8) Now empty the bottle and thoroughly clean it. Fill the bottle with only distilled water and weigh it. Let it be
W4 at temperature (Tx0 C).
9) Repeat the same process for 2 to 3 times, to take the average reading of it.

14
OBSERVATIONS & CALCULATIONS:
Table5
Calculations Group 1 Group 2 Group 3
Temperature 20o
C 23o
c / 20o
C
Mass Of Flask (W1) 106.6gm 106.25 gm 126.6492
Mass of soil in pycnometer (W3) 145.838gm 147.9 gm 151.0517 g
Mass of Flask + water + Soil (W2) 262.1656gm 376gm 257.3071g
Mass of flask + water (W4) 396gm 401 gm 395 g
Temperature Correction --------------- 0.9975 ----------------
Specific Gravity at Temp 23o
C
3.2688 2.493 1.8266
COMMENTS:

15
JOB NO:6
Hydrometer Analysis
OBJECTIVE:
This test is performed to determine the percentage of different grain sizes contained within a soil. The mechanical or
sieve analysis is performed to determine the distribution of the coarser, larger-sized particles, and the hydrometer method
is used to determine the distribution of the finer particles.
STANDARD REFERENCE:
ASTM D 422 - Standard Test Method for Particle-Size Analysis of Soils
SIGNIFICANCE:
The distribution of different grain sizes affects the engineering properties of soil. Grain size analysis provides the grain
size distribution, and it is required in classifying the soil.
EQUIPMENT:
 Balance,

16
 Set of sieves,
 Cleaning brush,
 Sieve shaker,
 Mixer,
 152H Hydrometer,
 Sodium hexameta phosphate
 Sedimentation cylinder,
 Control cylinder,
 Thermometer,
 Beaker
 Stopwatch
Fig.6a: Apparatus for plastic limit test
PROCEDURE:
 The soil must pass from sieve #200 more than 12 %.
 Take the 50 gram sample of soil passing through sieve #2000.
 Take 125 ml water and add 5 gram sodium Hexa-meta-phosphate (reagent) and mix the soil.
 If the soil do not dip in the water then add more water by the wash bottle.
 Stay the soil with water for 10-15 mints.
 Determine the zero correction.
 Determine the dispersing agent correction.
 Take 1000 ml water and add 5 gram sodium Hexa-Meta-Phosphate.
 Shake the soil for 1 mint.
 Put the hydrometer in the sedimentation jar and take the reading after 1, 2, 3, 4, 8, 15, 30, 45 and 60
mints.
 Similarly take the temperature simultaneously. Apply meniscus correction to the actual hydrometer
reading.

17
 Obtain the effective hydrometer depth L in cm (for meniscus corrected reading). For known Gs of the
soil (if not known, assume 2.7 for this lab purpose).
CALCULATION & OBSERVATION:
Table:6a
HYDROMETER ANALYSIS:
o Sp. Gravity = 2.7
o Meniscus correction = 1
o Zero Correction = 2.5
o Temperature correction = 3.8
TABLE:6b
time
(mint)
temp
actual
hydrometer
reading
hydrometer
reading
corrected
effective
depth
(L)
k from
table
D=
k√
Rc =
corrected
reading
+T.C.
+Zero
correction
a
p = (Rc x
a x
100)/Ws
%age
finer
0 30 30.5 31.5 11.4 0.01199 0 37.8 0.99 74.844 10.54331
1 30 28.5 29.5 11.6 0.01199 0.040836 35.8 0.99 70.884 9.985465
2 30 25 26 12.2 0.01199 0.029613 32.3 0.99 63.954 9.009232
3 30 24 25 12.4 0.01199 0.024376 31.3 0.99 61.974 8.730308
4 30 22 23 12.7 0.01199 0.021364 29.3 0.99 58.014 8.172461
8 30 13 14 14.2 0.01199 0.015974 20.3 0.99 40.194 5.662149
15 30 11 12 14.3 0.01199 0.011707 18.3 0.99 36.234 5.104302

18
30 30 2.5 3.5 15.9 0.01199 0.008729 9.8 0.99 19.404 2.733451
45 30 2.5 3.5 15.9 0.01199 0.007127 9.8 0.99 19.404 2.733451
GRAPH:6
COMMENT:
JOB NO:7
TO DETERMINE PERMEABILITY OF SOIL BY CONSTANT HEAD METHOD
REQUIRED APPARATUS:
 Constant head Permeameter device or apparatus.
 Constant elevation reservoir with water supply.
 Thermometer (Nearest to 1 C or 1F).
 1000-ml beaker.
 Balance, sensitive to nearest 0.01 g.
 Meter stic
 Plastic tubing.

19
 Stopwatch.
PROCEDURE:
o Measure the inside diameter of the Permeameter and record as D.
o Measure the length ‘L’ of the Permeameter, between the centers of the two piezometric tubes.
o Calculate the volume of the specimen needed for length L.
o For the given bulk-density and moisture constant calculate the weight of the soil, needed for the volume in step 3.
o Place the specimen in the Permeameter and allow water to flow through the sample for at least 10 min in order to
saturate it. Longer periods are sometimes required to ensure complete saturation of the sample. Bubbles that
appear (entrapped air) should be removed by tapping gently on the Permeameter or using other means.
o When constant flow conditions have been achieved, measure the hydraulic head ‘h’ across the sample.
o Using a 500 or 1000 cu-cm container (preferable 1000 cu-cm) record the time ‘t’ required to collect 1,000 cu-cm
of water. Repeal two or three additional times until two runs agree reasonably well.
o Measure and record the temperature of the test water as T C.
o Compute the K value at test temperature, also compute K20 (co-efficient of permeability at 20C
OBSERVATION AND CALCULATION:
TABLE:7
Test no H1 H2 H=H1-H2 t (V) Q=V/t T 0
C KT =Q.L/A.H
K20=KT
(
1 90.2 70.2 20 60 93 1.55 27 0.022445838
0.0191125
64
2 89.8 74.8 15 60 90 1.5 27 0.028962372
0.0246613
73
3 90.2 70.4 19.8 60 95 1.583333 27 0.023160146
0.0197207
95
4 90.6 68.8 21.8 60 93 1.55 27 0.020592512
0.0175344
62
COMMENTS:
JOB NO: 8
DIRECT SHARE TEST OF SOIL
OBJECTIVE:
To determine shear parameters of a soil with the help of direct shear test.
THEORY:
The shear strength of soil means is its property against sliding along internal planes within itself. The stability of
slope in an earth dam of hills and the foundation of the structure built on different types of soil depend upon the
shearing resistance offered by the soil along the possible slippage surface. Shear parameters are also used in

20
computing the safe bearing capacity of the foundation soils and the earth pressure behind retaining walls. Shear strength
is determined as below (after Coulomb)
The parameters c and for a particular soil depend upon its degree of saturatin density and the condition of laboratory
testing. In a direct shear test the sample is sheared along a horizontal plane This indicates that the failure plane is
horizontal. The normal stress on this plane is the external vertical load divided by the area of the soil sample. The shear
stress at failure is the external lateral load divided by the corrected area of soil sample. The main advantage of direct
shear apparatus is its simplicity and smoothness of operatio and the rapidity with which testing programmes can be
carried out. But this test has the disadvantage that lateral pressure and stresses on planes other than the plane of shear are
not known during the test.
APPARATUS:
 Shear box
 Container for shear box
 Grid plates
 Porous stone
 Base plate
 Loading pad
 Loading frame
 Proving ring with dial gauge
 Other Accessories
PROCEDURE:
For undisturbed specimen:
Specimen of required size (6 cm x 6 cm x 2.5 cm) shall be prepared from a natural undisturbed chunk. Weight
the mould empty and with the specimen also Fore remoulded specimen / Disturbed sample :The dried soil passing
though 2.36 mm sieve size is compacted at the desired density (and desired moisture content, if soil is to be tested
in moist conditions) in to the shear box after keeping both the halves of the shear box together by means of the fixing
screws. To insure the correct density of sample, take the weight of sample as multiplication of volume of soil 90 cm if
shear box size is (6 cm x 6 cm x 2.5) and desired density. Divide the sample in to two equal parts. One half of sample
should be fully consumed in to lower half of the box and other half should be fully consumed in upper half of the box.
Gentle tamping of the soil sample should be done while filling in the shear box. Keep the base plate, grid plate or porous
stone, before compacting the soil specimen in the shear box. For undrained test place the plain grid plate (non perforated )
below the porous tone. Care should be taken to see that serratios of the grid plate are at right angle to the direction so
shear For consolidation of specimen and testing at drained condition : Keep the perforated grid plate instead of
plain grid to enable to pore water of specimen to pass through. Weight the box with soil specimen to determine the
density of specimen. Keep the porous stone upper grid and loading pad on the soil specimen. Place the shear
box inside the container. Keep it on the loading frame. Make adjustment that the upper half of the box is in proper
contact with the proving ring assembly. Fill the container with water if the test is to be carried out at saturated condition.
Place a ball on the loading pad and mount the loading yoke on it. Adjust one on. Dial gauge on the loading pad to record
the vertical movement, (if required and other dial gauge on container to observe the shear movement. Put the weight on
the loading yoke to apply the normal stress of desired intensity. For consolidated undrained and drained test, the
full consolidation of the specimen should be permitted under this normal load. For unconsolidated undrained test
the consolidation step is avoid. Remove the fixing screws from the box and raise the upper half of the shear box by

21
about 1 mm, with the help of the spacing screws. The spacing screws pass only through the upper part of the box,
abutting against the top of the lower pat. Now adjust the dial gauges to zero and apply the shear load at the constant
rate of strain by a motorized gearing arrangement . Record the readings on proving ring and dial gauge for every
minute or so. Continue the test till specimen fails or at arrival of shear displacement of approximately 20 per cent
(1.2 cm in case of 6 cm x 6 cm shear box. This can be noted by shear dial gauge) of the specimen length.
Repeat the test observations on identical specimen under increasing normal stress corresponding to the field condition
and design requirements. Measure the moisture content of the soil before and after the test, if the test was conducted
on wet/ moist sample. At least three tests should be conducted on different normal loads.
PRECAUTIONS:
 The dimensions of the shear box should be measured accurately.
 Before allowing the sample to share, the screw joining the two halves of the box should be taken out.
 Rate of strain or shear displacement rate should be constant throughout the
 For drained tests, the porous stones should be saturated by boiling in water.
 Failure of the soil specimen is assumed when the providing ring dial gauge reading begins to recede
after reaching its maximum or at 20% shearing displacement of the specimen length.
COMMENTS:
JOB NO: 9
UNCONFINED (UNIAXIAL) COMPRESSION TESTING
INTRODUCTION:
In an unconfined compression test, a cylindrical core sample is loaded axially to failure, with no confinement (lateral
support). Conceptually, the peak value of the axial stress is taken as the unconfined compressive strength of the sample. In
addition to axial stress, axial and radial strains may be monitored during this test, to determine elastic constants (Young's

22
Modulus, E, and Poisson's ratio, v). In view of the variability of rock properties, when adequate samples are available,
repeat testing may be merited to determine average values.
TESTING EQUIPMENT AND SETUP:
One of several types of loading frames are available and can be used to perform this type of testing. Axial load is applied
with a servo-controlled hydraulic actuator. Available actuators can deliver up to 1.5 x 106 lbf. Axial stress is monitored
with a load cell. Axial and radial strains are measured using cantilever type strain transducers. When a rock is brittle, or
large deformation is expected, LVDTs may be used instead of cantilever devices. Occasionally, strain gages are attached
directly to the sample. Tests can be conducted at representative reservoir temperatures.
SAMPLE PREPARATION AND TESTING:
o A cylindrical sample, with a length-to-diameter ratio of two (common diameters are one, one and one-half, or
two inches, although numerous other sizes can be tested) is cut with an inert fluid and end-ground flat and
parallel, in accordance to ISRM standards (recommended tolerance in end parallelism is 0.001 inches).
o The sample is pre-saturated with an appropriate native fluid (or other desired fluids).
o The sample is installed between hardened steel end-caps and this assembly is sealed with a thin, deformable, heat
shrink jacketing material. Jacketing is not strictly necessary in unconfined compression testing, if the sample does
not come in contact with confining fluid.
o If strain measurements are being performed, axial and radial strain measurement devices are mounted on the
sample.
o Axial stress is applied to the sample. The axial stress is applied either at a controlled stress rate or a controlled
axial deformation rate. Loading is continued until the sample fails. If behavior is not brittle, loading is continued
so that the post-peak regime is adequately defined.
o The failed sample is examined, documented and archived in a specified manner.
Test Results And Calculations:
Experimental results are represented as stress-strain curves, and tabulated values of elastic constants and strength. shows
example stress-strain curves for one particular sample. The stress-strain data are used in determining the compressive
strength and elastic constants, as described below. In a brittle or elastic-perfectly plastic or strain softening material,
unconfined compressive strength is taken as the maximum axial stress accommodated by the sample. When strain
hardening occurs, other criteria are adopted. Elastic constants are determined over linear sections of the stress-strain
curves, often in the range of 20 to 70% of the maximum applied axial stress. Generally, this, or a similar stress range,
ensures that the calculated static elastic properties are obtained from a linear portion of the stress-strain curves.
Why is Unconfined Compression Testing Performed:
o To provide an important data point for determining a failure locus (i.e. Mohr envelope).
o For defining parameters needed in constitutive modeling.
o As an indicator of wellbore stability.
o As a component in wellbore stability and sand production numerical or Analytical calculations.
o For mine and excavation design.
o For coal bed methane cavitation design.

23
COMMENTS:
JOB NO: 10
TRIAXIAL COMPRESSION TESTING
INTRODUCTION:

24
In a conventional triaxial compression test, a cylindrical core sample is loaded axially to failure, at constant confining
pressure. Conceptually, the peak value of the axial stress is taken as the confined compressive strength of the sample. In
addition to axial stress, axial and radial strains may be monitored during this test, to determine basic elastic constants
(Young’s Modulus, E, and Poisson’s ratio, ν). If triaxial testing is performed at several confining pressures, and
preferably if unconfined compression and tensile test data are available, a representative failure locus can be constructed.
The selected confining pressures for triaxial testing are generally spread over a range from very low to beyond the
maximum anticipated in-situ effective stress conditions. Measurements can be performed at in-situ temperature and pore
pressure can be applied.
TESTING EQUIPMENT AND SETUP:
A triaxial compression system is used to perform this type of testing. Axial load is applied with a servo-controlled
actuator. Confining pressure and pore pressure are hydraulically generated. Axial force up to 1.5 x 106 lbf can be applied
to samples up to ten inches in diameter. Axial and radial strains are measured using cantilever type strain transducers.
When a rock is brittle, or large deformation is expected, LVDTs may be used instead of cantilever devices. Occasionally,
strain gages are attached directly to the sample.
SAMPLE PREPARATION:
o A cylindrical sample, with a length-to-diameter ratio of two (common diameters are one, one and one-
half, two inches...although numerous others can be tested) is cut with an inert fluid and end-ground flat
and parallel, in accordance to ISRM standards (recommended tolerance in end parallelism is ± 0.001
inches).
o The sample is pre-saturated with an appropriate native fluid (or other desired fluids).
o The sample is installed between hardened steel end-caps and this assembly is sealed with a thin,
deformable, heat shrink jacketing material.
o The jacket prevents confining fluid from penetrating into the sample and allows independent control and
monitoring of the confining and pore pressures during testing.
o The end-caps are ported to allow application of pore pressure and/or flow if permeability is measured.
o If strain measurements are being performed, axial and radial strain measurement devices are mounted
on the sample fixture.
TESTING:
The procedures for conducting a triaxial compression test are, for the most part, relatively standardized. The assembled
sample and instrumentation fixtures are installed in a pressure vessel. After this, typical procedures might include the
Following steps:
 Fill the pressure vessel with hydraulic confining fluid. Raise the confining pressure (σ3) to a nominal value (100
psi) at a servo-controlled rate (3 psi/s for example). This initial confining pressure is applied so that there will

25
always be at least a small difference between confining pressure acting outside of the jacket and pore pressure in
the rock (inside the jacket). Otherwise leakage will occur.
 Often, freezing is used to maintain the integrity of unconsolidated samples during preparation. Obviously, this is
not desired; however, it is sometimes the only feasible method of preparing such samples. For frozen samples, a
period a thawing is allowed. Strains are allowed to equilibrate.
 If additional saturation measures are required, they are often undertaken at this time. Vacuum back filling may be
adopted.
 The confining pressure (σ3) and the pore pressure (Pp) are simultaneously increased at a controlled rate (for
example, 1 psi/s) until the pore pressure reaches a target value.
 The pore pressure is maintained constant and the confining pressure is increased, at a controlled rate, until σ3
reaches a specified value.
 The axial stress difference (σ1-σ3) is increased at a rate corresponding to an axial strain rate of 10-5/s.
Alternatively, rather than controlling the axial strain rate, the axial stress rate can be controlled. Loading is
continued until the sample fails. If behavior is not brittle, loading is continued so that the post-peak regime is
adequately defined.
 The sample is unloaded slowly, the pressure vessel is emptied and the sample assembly is disassembled. The
sample is examined, documented and archived in a specified manner.
TEST RESULTS AND CALCULATIONS:
Experimental results are represented as stress-strain curves, and tabulated values of elastic constants and strength. Figure
1shows example stress-strain curves for one particular sample. The stress-strain data are used in determining the
compressive strength and elastic constants, as described below. Figure 2. Typical stress-strain curves, showing axial and
radial strains (radial strains are measured at 90° to each other), as a function of the axial stress difference. In brittle or
elastic-perfectly plastic or strain softening materials, confined compressive strength at the confining pressure used in a
triaxial test is taken as the maximum effective axial stress (total axial stress minus a percentage of the pore pressure)
accommodated by the sample
Failure Envelope And Strength Parameters:
A failure envelope is a representation of the strength of a material at various values of confining pressure which could
exist in-situ. The simplest representation of this is linear and is known as the Coulomb failure envelope. This failure locus
is a best fit tangent to Mohr’s circles, constructed from multiple triaxial compression, uniaxial compression and tensile
tests
COMMENTS:
JOB NO: 11

26
CONSOLIDATION TEST OF SOIL
OBJECTIVE:
To determine the co-efficient of consolidation and compression index.
cc = compression index
cv = co-efficient of consolidation
CONSOLIDATION:
It is the method by which the density of soil is increased because of eruption of water from soil mass under the applied
load (load of building & structure).
THEORY:
When a structure is built on a saturated soil the load is generally carried at first by incompressible water with in the soil
because of extra load on soil water will tend to remove from the voids in soil causing the reduction in the void volume and
settlement of structure in case of high permeability soils (coarse grain soil, gravel and sand). The process required a short
interval for low completion however in soil of low permeability (fine grain soil).the process required a long time interval
for completion. The result is that strain occurs very slowly thus settlement will take place slowly and will continue over a
long period of time.
PURPOSE:
This test is performed to determine the size and Rate of volume decrease the latterly confined soil sample under goes
when subjected to different vertical pressure from the find outd data consolidation curve can be plotted (pressure-void
relationship).This data is used in determining co-efficient of consolidation cc & cv and re-compression index (CR) and
pre-consolidation pressure (it is the pressure which has been applied on the soil in the past).
REFERENCE:
AASHTO-T216-66.Standard test for the one dimensional consolidation properties of soil (Cc,, Cv and CR)
TYPES OF CONSOLIDATION:
There are two types of consolidation.
1. Floating Consolidometer
2. Fixed Consolidometer
In the floating consolidometer compression of sample occur from top & bottom both. But in the fix consolidometer
compression of sample occur only in the downward direction but the floating ring device can’t be used for permeability
test But fixed in device can be used.
Tools Required:
 Moisture cane
 Filter paper.
 Dial gauge (least count=0.001 inch).
 Sample trimming device
 Glass plate (without glass).
 Clock
PROCEDURE:

27
 Carefully find out the dimension of consolidation ring.
 Find out its empty weight.
 Carefully trim a specimen to fit the consolidation ring.
 Find out its weight with sample.
 Place some of trimmed soil for moisture content determination. Also find the specific gravity of soil solids.
 Carefully place soil sample in the consolidometer with the pores stones on each face. Be sure the pores stone will
ring so that test can proceed satisfactory.
 Place consolidometer in the loading device and attach the dial gauge.
 At a convenient starting time apply the first load increment & simultaneously take determination reading at
passed time of 0.25,0.5,1,2,4,8,16,30,60,120 up to 24 hour.
 After the 24 hours or when ΔH b/w two reading is sufficiently small change the load to next loading increment.
 Continue change loads and taking elapsed time vs. deformation time reading through the load range of
consolidometer. Until the deserved pressure has been obtained.
 Place the sample in oven at the end of test to find the weight of soil solids and to enable the computation of final
moisture content.
 Plot curves of dial reading vs. loading time curve are plot dial reading vs time for any two load increment
Compute the compression index.
COMMENTS:

SOIL MOISTURE ANALYSIS

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