LABORATORY TEST and PREPARATION OF REPORT
Use of Equipment
Laboratory equipment is never cheap. For accurate experimental results, the equipment
should be properly maintained. The calibration of certain equipment, such as balances
and proven rings, should be checked from time to time. It is always necessary to see that
all equipment is clean before and after use. Better results will be obtained when the
equipment being used is clean, so always maintain the equipment as if it were your own.
Recording the Data
In any experiment, it is always a good habit to record all data in the proper table
immediately after it has been taken. Oftentimes, scribbles on scratch paper may later be
illegible or even misplaced, which may result in having to conduct the experiment over,
or in obtaining inaccurate results.
Report Preparation
In the classroom laboratory, most experiments described herein will probably be
conducted in small groups. However, the laboratory report should be written by each
student individually. This is one way for students to improve their technical writing
skills. Each report should contain:
1. Cover page – This page should include the title of the experiment, name and date on
which the experiment was performed. (see example)
2. Following the cover page, the items listed below should be included in the body of the
report;
 Objective(s) of the experiment
 Theory
 Equipment used
 A schematic diagram of the main equipment used
 A brief description of the test procedure
3. Results – This should include the data sheet(s), sample calculation(s), and the required
graph(s).
4. Graphs and Tables – Graphs should be made as large as possible, and they should be
properly labeled. Always give the units.
5. Conclusion(s) – A discussion of the accuracy of the test procedure should be included
in the conclusion, along with any possible sources of the error.
6. Bibliography and/or Reference.
Report Writing
A soil report should follow good technical report writing form, including the citing of any
references used. Do not use the first person (I, me, we, our, …etc.) in writing a
technical report. Do not write such statements as, “I found that…” or “My group
found…”, in stead use “It was found that …” Use correct spelling, when in doubt,
consult the dictionary.
1
Department of Civil and Environmental Engineering
Geotechnical Engineering Laboratory
Soil Laboratory Testing Report
Experiment Title: ______________________________________________________
Experiment No: _________________
Group No:_____________________________________________________________
Name:________________________________________________________________
Testing Date___________________________________________________________
Submission Date________________________________________________________
2
CIVL 351 Soil Mechanics I
Laboratory Test
Laboratory #1: Field Identification of Soil and Sieve Analysis
Objectives
Part 1: Field Identification of Soil
(a) To identify the classification of the soil by its size, colour and hardness.
(b) To classify silt and clay by dilatancy test.
Part 2: Sieve Analysis
To obtain the grain size distribution and grading characteristics of the soil particles in a
given soil sample.
Part 1:
Visual Classification of Granular Soils
Several soil types found in the area will be available for your visual classification.
1.For each of the sample approximate the percentages of sand and gravels adding to
about 100%.
2. Describe the sample be including:
a. Color
b. Gradation
c. Soil subdivisions
d. Presence of fines
e. Grain shape
Visual Classification of silt and clay
Base on dilatancy:
Moisten the soil sufficiently to make it soft, but not sticky. Place this pat of soil in the
open palm of one hand and tap the side of this hand sharply with the other hand; repeat
this several times. Dilatancy is exhibited if, as a result of this tapping, a glossy film of
water appears on the surface of the pat. If the pat is now pressed gently the water will
disappear from the surface and the pat becomes stiff again. Very fine sands and
inorganic silts exhibit marked dilatancy, whereas clays and medium-to-coarse sands do
not.
Part 2: Sieve Analysis
Equipment:
Standard brass sieves.
Balance sensitive to 0.1g.
Containers
Sieve.
Oven.
3
Procedure:
1. Collect a representative dry sample of approximately 500g.
2. Determine the mass of your sample accurately to 0.1g. Record as W.
3. Prepare a stack of sieves. A sieve with a larger opening is placed above a sieve
with smaller openings. The sieve at the bottom should be No.200. A bottom
pan should be placed under sieve No.200. Generally the sieves used in a stack
are No.4, 10, 20, 40, 60, 100, 200 ; however, more sieves can be placed in
between.
4. Pour the soil prepared in step 2 into the stack of sieves from the top.
5. Place the cover on the top of the sieves.
6. Run the stack of sieves through the sieve shaker for about 5 minutes.
7. Stop the sieve shaker and remove the stack of sieves.
8. Weigh the amount of soil retained on each sieve and the bottom pan. Record as
W1.
9. Calculate the total weight of soil retained on all sieves. The percentage loss
during sieve analysis=(W-W1)/W*100 and must be less than 2% in order to
validate the test.
Results:
1.Describe the soil using the USCS system.
USCS for coarse grained soils
Coarse grained means that greater than 50% is retained on the No.200 sieve.
For coarse grained soils:
Determine if it is sand or gravel. If greater than 50% is retained on No.4 sieve
then it is gravel (G), if greater than 50% passes No.4 sieve then it is sand (S).
Then,
a) Determine if it has appreciable fines. If greater than 12% passes No.200 sieve
then classify as GM, GC, SM, SC depending on if it is sand or gravel and if the
fines are silt (M) or clay (C).
b) If there are not many fines, then look at the gradation. If it is well graded then
classify as GW or SW and if it is poorly graded then classify as GP or SP.
2. Plot a Grain size distribution curve for the sieving test.
3. From the graph, find the coefficients of uniformity Cu and curvature Cc from D10 , D30 ,
D60 , the grain size corresponding to 10, 30, and 60% weight finer.
Discussion Questions:
1. What is the purpose of particle size distribution?
2. Under what conditions should you use wet sieving analysis instead of dry sieving?
3. On what range of particle size does the sieve analysis apply
4. Is it possible to carry out a sieve analysis on a sample of clay?
4
Sieve
number
Sieve size
(mm)
Mass
Retained(g)
%
Retained
5
%
Cumulative
%
Passing
CIVL 351 Soil Mechanics I
Laboratory Test
Laboratory #2: Atterberg Limits of Soil
Objective
To familiarize the general relationship between moisture content and the boundaries of
states of soils in terms of limits (ie. liquid limit and plastic limit)
Part 1. Determination for LL
Equipment
For Casagrande Method
Casagrande cup and base setup
Flat glass plate
Metal cups
Apparatus for water content determination.
Wash bottle for adding controlled amount of water to soil sample.
For Cone-Penetration Method
A flat glass plate
Two palette knives or spatulas and one straightedge
A penetrometer with the cone
One or more metal cups not less than 55 mm in diameter and 40 mm deep with
the rim parallel to the flat base
A wash bottle
Balance
Apparatus for moisture content determination
Liquid limit-Casagrande Method
1. Place a portion of the soil sample in the brass cup. The surface of the soil paste
should be smoothed off level and parallel to the base, giving a depth at the
greatest thickness of 10mm.
2. A groove is cut through the sample from back to front, dividing it into two equal
halves.
3. Turn the crank handle at a steady rate of two revolutions per second, so that the
bowl is lifted and dropped. Continue turning until the two halves of the soil pat
come in contact at the bottom of the groove along a distance of 13mm.Record the
number of blows required to close the groove.
4. Remove 5 to 10g of soil from the sample and use it to determine the water content
of the complete specimen.
5. Repeat 1 to 4 with different water content.
6
Liquid limit-Cone-penetration Method
1. Take a sample of about 300 g from the soil paste and place it on the glass plate.
2. Mix the paste and push a portion of the mixed soil into the cup with a palette
knife.
3. Place the cup under the center of the cone.
4. Gradually lower the stem until the tip of the cone is exactly in contact with the
surface of the sample.
5. Take the reading of the point on the gauge to 0.1 mm. This is the first reading.
(R1)
6. Adjust the automatic release and locking device.
7. Press the start button.
8. After the 5 sec. countdown finished, take a second reading to 0.1 mm (R2)
9. Record the difference between the two readings (R2-R1). This is the first cone
penetration.
1. 10 Lift out the cone and clean it carefully to avoid scratching.
10. Take a moisture content sample of about 10 g from the area penetrated by the
cone and determine the moisture content.
11. Repeat at least three more times using the same sample of soil to which further
increments of distilled water (about 4- 5cc) have been added. Proceed from the
drier to the wetter condition of the soil. The amount of water added shall be such
that a range of penetration values of approximately 15 mm to 25 mm is covered
by the four or more test runs and is evenly distributed.
Part2: Determination of PL
Equipment
1. A flat glass plate, smooth and free from scratches, on which threads are rolled.
2. Two palette knives or spatulas.
3. Apparatus for the moisture content determination.
4. A length of rods, 6 mm and 3 mm in diameter and about 100 mm long.
Plastic limit
1. Put approximately 20g of a representative, dry sample passing the No.40 sieve,
into a dish.
2. Add water from the plastic squeeze bottle to the soil and mix thoroughly.
3. Determine the mass of a moisture can and record it ( W1 ).
4. From the moist sample, prepare several ellipsoidal-shaped soil masses by
squeezing the soil with your fingers.
5. Take one of the ellipsoidal-shaped soil masses and roll it on a ground glass plate
using the palm of your hand.
6. When the thread that is being rolled reached1/8 in (3mm) in diameter (compare
with the glass rod at your station), break it up into several small pieces and
squeeze it with your fingers to form an ellipsoidal mass again.
7. Repeat steps 5 and 6 until the thread crumbles into several pieces when it reaches
a diameter of 1/8 in. It is possible that a thread may crumble at a larger diameter
7
during the rolling process, whereas it did not crumble at the same diameter during
the immediately previous rolling.
8. Collect the small crumbled pieces in the moisture can and cover the can.
9. Take the other ellipsoidal soil masses formed in step 4 and repeat steps 5 to 8 until
you have approximately 20g of wet soil.
10. Determine the mass of the moisture can plus wet soil ( W2 ).
11. Dry the soil in the can and determine the mass of the can plus dry soil ( W3 ).
12. Repeat steps 4 to 11 two more times.
Calculations:
1. Determine the plastic limit from:
W  W3
PL  2
W3  W1
2. Determine the plasticity index from:
PI  LL  PL
Discussion Questions
1. What are the definitions of liquid and plastic limits? Are these definitions based on
theoretical or empirical concepts?
2. Is it possible for a soil to have a liquid limit and a plasticity index (PI) both equal to
30%? Why?
3. What is the activity of clays? What is it used for?
8
Plastic Limit Table
1
2
Test No
Container No
Mass of wet soil + container (m2)
g
Mass of dry soil + container (m3)
g
Mass of container (m1)
g
Mass of moisture (m2 – m3)
g
Mass of dry soil (m3-m1)
g
Moisture content=(m2-m3)/(m3-m1)
3
Average
%
Liquid Limit Table (cone-penetration)
1
2
Test No
Initial dial gauge reading R1 mm
Final dial gauge reading R2 mm
Penetration (R2 – R1) mm
Container No
3
4
Liquid Limit Table (Casagrande Method)
1
2
3
4
Mass of wet soil + container (m2)
g
Mass of dry soil + container (m3)
g
Mass of container (m1)
g
Mass of moisture (m2 – m3)
g
Mass of dry soil (m3-m1)
g
Moisture content=(m2-m3)/(m3-m1)
Test No
Number of Blow
Container No
4
%
Mass of wet soil + container (m2)
g
Mass of dry soil + container (m3)
g
Mass of container (m1)
g
Mass of moisture (m2 – m3)
g
Mass of dry soil (m3-m1)
g
Moisture content=(m2-m3)/(m3-m1)
%
9
CIVL 351 Soil Mechanics I
Laboratory Test
Laboratory #3: Permeability of Soils
Objectives:
1) To measure the coefficient of permeability of a sand by constant head method
Equipment:
Permeameter.
Constant-head filter tank.
Manometer tubes.
Thermometer.
Stop watch.
Graduate cylinder.
Procedure:
1. The water enters at the bottom of the plastic chamber, flows through the sand
column, and flows out to the sink through the outlet at the top. Standpipes are
equipped at three locations to measure the pore pressures.
2. Measure the diameter, D, and length L, of the sand column. Measure the
elevation heads of three standpipes (taking the level of the bottom standpipe as
the datum). The specific gravity and the void ratio of the sand will be given in the
lab.
3. Supply the water at the bottom of the permeameter and allow the flow to continue
for about 10 minutes to saturate the specimen.
4. After steady state flow is establish (i.e. the levels of the water in the standpipes
are constant), collect water flowing out of the chamber in a graduated cylinder or
beaker. Record the time of collection and weigh the water collected so that an
average flow rate can be established. Record the water levels in all of the 3
standpipes.
5. Increase the flow rate and repeat step4.
6. Continue to increase the flow rate until quick conditions occur. You will see your
“house” start to sink into the sand.
Calculations:
The permeability is calculated from:
k
QL
Aht
where h is the head difference- use the difference between standpipes 1 and 3 for your
calculations.
The value of k is usually given for a test temperature of water at 20 o C. So to
calculate
10
k 20o C  kT oC
T C
 20 C
o
o
where the ratio of viscosities can be obtained from Table1.
Questions:
1. Plot the differences in total heads ( h12 , h23 ) versus flow rate. Determine the
coefficient of permeability (cm/sec) of the sand specimen. Comment on any nonlinearity observed from the plot.
2. Plot the elevation head, pore pressure head, and total head (x-axis) along the
height of the chamber (y-axis) at quick sand conditions. Also, include the hydrostatic
head (when no seepage takes place) and comment on the effect of seepage on pore
pressure.
3. Calculate the hydraulic gradient required for occurrence of ‘quick sand’ and
compare the value with that observed in the laboratory.
Constant Head Permeability Test
Length of specimen, L = ________cm
Diameter of specimen, D = ________cm
Area of specimen, A = ________ cm 2
Volume of specimen, V = ________ cm 3
Specific Gravity, Gs = ________
Void ratio, e = _______
Initial conditions
Standpipe
1
2
3
Elevation head, z
_________
_________
_________
Table 1- Variation of the viscosity of water with temperature
T(
O
T C
 20 C
C)
O
O
15
16
17
18
19
20
21
22
23
24
25
26
1.135
1.106
1.077
1.051
1.025
1.000
0.976
0.953
0.931
0.910
0.889
0.869
11
Test No
1
Mass of water
collected, M w (g)
Temperature of
water, (T O C )
Time of
collection, t (s)
Average flow,
Q( cm 3 )
Pressure head
2
3
Standpipe 1
Standpipe 2
Standpipe 3
Head difference
(cm)
Permeability, k
(cm/sec)
Average k = _______________cm/sec
k 20o C
= ________________cm/sec
12
4
5
CIVL 351 Soil Mechanics I
Laboratory Test
Laboratory #4: Relative Density and Compaction
Objectives
(a) To determine the maximum density and minimum density
(b) To determine the relationships between compacted dry density and soil moisture
content.
Part1. Relative density
Equipment
Mould
Funnel
Balance
Surcharge
Vibrating Table
A. Minimum Density
1. Determine the volume of the mold by measuring the height and diameter.
2. Weigh the mold.
3. Place the soil particles in the mold as loosely as possible. Pour the soil
from a funnel in a steady stream while at the same time adjusting the
height of the spout so that the free fall of the soil is 2.5cm. Move the
pouring device in a spiral motion from the outside toward the center to
form a layer of uniform thickness without segregation. Fill the mould 2 to
3 cm above the top and scrap off the excess soil level with the top by
making one continuous pass with a steel straightedge.
4. Weigh the mould and soil and estimate the density.
5. Repeat to obtain 3 results. Use the minimum.
B. Maximum Density
1. Follow steps 1 and 2 as above.
2. Assemble the collar on the top of the mold. Fill the mold and collar as
described above. Use the weights available in the laboratory. Apply the
surcharge weigh on the sample surface (about 14kPa, confirm this
pressure in the lab). Place the assembled mold on the vibrating table for 5
minutes. Remove the surcharge weights and collar from the mold. Scrap
off the excess soil level with the top by making one continuous pass with
as straightedge.
3. Weigh the mold and estimate the density.
4. Repeat to obtain 3 results. Use the maximum.
C. Questions
1. What are the minimum and maximum void ratio and porosities for the soil
sample?
13
Part2. Compaction
Equipment
Compaction Mold.
Drop hammer.
Sample extruder.
Metal straightedge.
Mixing tools.
Procedure:
1. Record the details about the weight of hammer and hammer drop which will be
given in the laboratory.
2. Obtain about 3800g of dry soil. Break all lumps in the soil.
3. Determine the volume of the compaction mold by measuring its height and
diameter.
4. Determine the mass of the compaction mold plus base plate (do not include the
collar extension) ( W1 ).
5. Estimate the amount of water to be added to reach the desired water content
which is about 4-5% below the optimum moisture content (OMC). The OMC
will be given in the lab. Mix the water and soil thoroughly.
6. Attach the collar extension to the compaction mold.
7. Place the moist soil into the mold in three equal layers. Each layer should be
compacted uniformly using the Standard Proctor hammer 25 times before the next
layer of loose soil is added. Note: The layers of loose soil that are being placed
into the mold should be such that at the end of the three layer compaction, the soil
should extend slightly above the top of the rim of the compaction mold.
8. Remove the collar from the mold. Be careful not to break off ant of the
compacted soil inside the mold while removing the collar. Note: If the soil breaks
off below the rim, or if the last layer of compacted soil is not above the rim, then
you must redo the compaction.
9. Using a straight edge, trim the excess soil above the mold. Now the top of the
compacted soil will be even with the top of the mold.
10. Determine the weight of the mold + base plate + compacted moist soil ( W2 ).
11. Remove the base plate from the mold and extrude the soil from the mold.
12. From the moist soil extruded, take two samples from the center and determine the
moisture content. To determine the moisture content, first weigh a cup ( W3 ), then
determine the mass of the cup and wet soil ( W4 ), and the mass of the cup and dry
soil ( W5 ), to calculate the moisture content. Take the average of the two moisture
contents.
13. Break the rest of the compacted soil by hand down to its original size in the tray.
Add more water to increase the water content of the soil by 2% based on the
original soil weight.
14. Carefully remix the soil and repeat steps 6 to 13 until the mass of the mold+ base
plate+ moist soil ( W2 ) begins to decrease. Continue the test until at least two
successive down readings have been obtained.
14
Calculations:
1. Determination of the bulk (moist) unit weight:
MassofMois tSoil (W2  W1 ) * g
VolumeofMold
where g is 9.81 m / s 2 and  should be in KN / m 3
 
2. Determination of the dry unit weight:
d 

1
3.Plot a graph showing unit weight  d against water content  .
Questions:
1. What is the optimum water content and the maximum dry unit weight?
2. Plot the zero air voids (ZAV) line (i.e. S r =100%) on your graph. Show a sample
of your calculation.
3. Explain why no portion of your compaction curve should plot to the right (i.e
cross) the ZAV line.
15
Compact Dry Density Determination
Volume of mould (V) _____________________cm3
Test number
Mass of mould + compact specimen (m1) g
Mass of mould (m2)g
Mass of compact specimen (m1 – m2) g
Bulk Density ρ = (m1 – m2)/V
Mg/m3
Dry Density = 100 ρ/(100 + w) Mg/m3
Moisture Content Determination
Container number
Mass of wet soil+ container(m3) g
Mass of dry soil + container (m4) g
Mass of container (m5) g
Mass of moisture (m3 – m4) g
Mass of dry soil (m4 – m5) g
Moisture Content w = (m3-m4)/(m4-m5)×100 %
16