Geotechnical Permeability Testing Methods

This assignment presents an analysis of geotechnical permeability testing performed on a soil sample using two different methods. The data obtained from each method is presented, along with calculations for determining permeability values. The results are then discussed, highlighting any discrepancies or similarities between the two approaches. References to relevant geotechnical engineering texts are included.

Geotechnical Lab Report1
Geotechnical Lab Reports
Name
Professor
University
City, State
Date

Geotechnical Lab Report2
Geotechnical Lab Reports
Proctor’s Compaction Test
Introduction
Soil compaction refers to the process whereby the soil particles of a sample are compacted using
mechanical compressive means, so as to increase the density of the soil. The moisture content of
the soil is the factor used to determine the maximum dry density of the soil sample used, while
the variables include the soil type as well as the mass of soil used (Terzaghi & Peck, 2007).
Procedure
The mass of the mold and the plate were taken, and the soil sample was passed through the
19mm sieve. The sample was then prepared by placing the mold on a flat surface and it was
filled into the mold in three layers, each of which was rammed and compacted by 25 blows
before the next layer was filled. The assemblage was then weighed and the moisture content of
the sampled determined. The setup was then cleaned up, and water was added to increase the
moisture content of the sample. The procedure was then repeated until all the results were
collected.
Results
Mass of moisture container + Wet soil = 1.367kg
Mass of mould: 5081g
Volume of mould: 994.51 cm3

Geotechnical Lab Report3
Average moisture content
Test
No.
Moisture
Container
No.
Mass of
Moisture
Container
Mass of
Moisture
Container
+ Wet
Soil
Mass of
Moisture
Containe
r + Dry
Soil
Moisture
Content
(w)(%)
226 35.7 113.7 110.4 4.4
4 44 149.9 145.3 4.5
104 37.8 113.3 110.3 4.1
241 36.1 126.7 122.4 4.9
124 38.7 114.3 111 4.5
207 35.8 158 153.2 4
125 39.1 145 141.1 3.8
13 43.5 150.3 146 4.1
239 36.9 166.7 161.1 4.5
Average 4.31
Test
No.
Mass of
mould +
soil (m2)
Mass of
Soil
Bulk
Density
of Soil
(p)
Dry
Density
of Soil
(pd)
1 7026.1 1945.1 1.96 1.88
2 7183.3 2102.3 2.11 2.02
3 7297.8 2216.8 2.23 2.14
4 7283.2 2202.2 2.21 2.11
Moi
stur
e
Cont
aine
r
No.
Mass of
Moisture
Container
Mass of
Moisture
Containe
r + Wet
Soil
Mass
of wet
Soil
Mass
of
Moistu
re
Contai
ner +
Dry Soil
Mass of
moistur
e
contain
er +Dry
soil 2
Average Mass of
Dry soil
moistu
r
conten
t
Moistu
re
Conten
t (w)
(%)
R18 156.6 2192.7 2036.1 2070.4 2072.6 2071.5 1914.9 0.0633 6.33
R3 555.1 2654.3 2099.2 2479 2480.7 2479.85 1924.7 0.0907 9.07
R9 353.6 2567.5 2213.9 2336.9 2339.1 2338 1984.4 0.1157 11.57
4 491.5 2691.8 2200.3 2416.1 2418 2417.05 1925.55 0.1427 14.27

Geotechnical Lab Report4
5 6 7 8 9 10 11 12 13 14 15
1.7
1.75
1.8
1.85
1.9
1.95
2
2.05
2.1
2.15
2.2
The plot of Dry Density against Moisture
content
Moisture content (%)
Dry Density (g/cm3)
Maximum Dry Density = 2.14 g/cm3
Moisture content = 13%
Discussion and conclusion
This experiment establishes the optimal M.C of the soil sample at which it will increase its
density and thus reach its maximum dry density. The maximum dry density is achieved from the
peak point of the curve and the M.C at that point is the optimal M.C of the soil sample.
Compaction causes the bulk density of soil to increase as most of the void space is occupied after
the sample is compacted. The moisture content of the sample however determines this aspect as
the water particles are not driven out causing the soil to approach saturation. Adding more water
increases the bulk density, however this phenomenon changes as saturation is approached
(Terzaghi & Peck, 2007).
Cone Penetrometer Test
Introduction

Geotechnical Lab Report5
This test is an in-situ methodology used to assess the unconsolidated sediments in the soil
that is near the earth’s surface. The test which can be performed both under water and on land
assesses the properties of the soil both during and even after the penetrations has been conducted
on the site (Das, 2015).
Procedure
In this test the end of the cone penetrometer device is pushed into the ground site at a constant
rate and the resistance on the soil to the penetration of the penetrometer device and the sleeves
which was made at a constant rate.
Result
Penetration Readings
Sample
No.
Cone Penetration (mm)
1 2 3 4 Average
1 15.4
1
15.9
3
- - 15.67
2 22.2
1
20.3
2
21.0
1
- 20.67
3 21.1
2
22.9
4
21.3
0
21.1
9
21.25
4 21.8
3
21.8
9
- - 21.86
Pentration & Moisture Content Data
Sample No.
1 2 3 4
Average Penetration (mm) 15.67 20.67 21.25 21.86
Moisture Cup No 226 141 140 125
Moisture Cup Mass - m1 (g) 35.7 38.7 37.7 39.1
Mass of Wet Soil + Cup - m2
(g)
68 79.1 79.6 89.2
Mass of Dry Soil + Cup - m3
(g)
58.73
6
66.79
7
66.63
9
73.49
2
Moisture Content 40.22 0.437
9
0.437
5
0.456
7

Geotechnical Lab Report6
39 40 41 42 43 44 45 46 47
0
5
10
15
20
25
A plot of penetration depth against
moisture content
Moisture content (%)
Penetration depth (mm)
Linear Shrinkage and Plastic Limit Tests
Introduction
In this test, the Atterberg limits and their relationships to each other are used to determine the
consistency limits of a soil sample and its behavior in different situations. This assessment
depends on the bulk density of the soil sample. The plastic limit represents the level of water
where the soil sample will start to exhibit plasticity. The linear shrinkage on the other hand
represents the ratios of the swelling and shrinking of the soil sample (Das, 2015).
Procedure
The sample of soil slightly wet soil was rolled into a thread, until it begins to crumble. The linear
shrinkage is found from drying the soil l to establish the level of shrinkage of the soil sample.
Results
Plastic Limit
Moisture Cup number 4 9
Moisture Cup Mass 44 44.1

Geotechnical Lab Report7
Mass of wet soil + cup: m1 (g) 63.7 57.7
Mass of Dry Soil + cup: m2 (g) 60.67 55.753
Moisture Content (%) 18.17 18.25
Linear Shrinkage
length of the mould 124.5
8
124.7
4
124.8
3
124.71
7
Longtitudinal shrinkage of specimen air dry 109.4
9
110.2
6
110.2
4
109.99
7
Longtitudinal shrinkage of specimen 108.6
7
108.4
3
106.9
1
108.00
3
Linear shrinkage % 12.77 13.08 14.36 13.40
Discussion and Conclusion
The shrinkage limit was the limit to which the soil sample contracts after it loses its water from
drying.
Sieve Analysis Experiment
Introduction
The compaction test is an important test in soil mechanics which aims to determine the grain size
distribution of a soil sample through passing the sample through a series of sieves. Soils whose
particles are larger than 0.075 mm in diameter are classified as coarse grained soils and the grain
size distribution informs about the gradation of the soil as either well or poorly graded. Passing
the soil sample through a series of sieves allows for proportioning of the soil particle sizes and
thus the distribution of the soil particles (Terzaghi & Peck, 2007) p. 729). sieves by percentage is
plotted against the dimension diameter of the sieve.
Procedure
The apparatus of the test required include a weighing balance, a series of 12 sieves of
different sizes and a sieve shaker. The soil sample was first oven dried and passed through the

Geotechnical Lab Report8
other sieves when the shaker was started. The soil remaining on each sieve was then measured
and the results were recorded.
Results
Mass of Test Sub-sample (m1) 995 g
Sieve Size
(mm)
(1) Mass
Retaine
d (g)
(2) %
Retained
(3)
Cumulative
% Retained
(4) %
Passing
19.00 65 6.53 6.53 93.47
9.50 42 4.22 10.75 89.25
4.75 36 3.62 14.37 85.63
2.36 47 4.72 19.10 80.90
1.18 16 9.38 28.48 71.52
0.600 30 17.59 46.06 53.94
0.425 16 9.38 55.44 44.56
0.300 17 9.97 65.41 34.59
0.150 27 15.83 81.24 18.76
0.075 20 11.73 92.96 7.04
Pan 11 6.45 99.41 0.59
TOTAL 99.41
-1.5 -1 -0.5 0 0.5 1 1.5
0
0.5
1
1.5
2
2.5
Grain particle distribution Curve
Diameter Size
Percentage Finer

Geotechnical Lab Report9
D10= 10.03mm
D30= 1.0593 mm
D60 = 0.3981mm
Cu= D60/ D10
= 0.3891/10.03
Cc= (D30)2 / D10 X D60
=1.05932 / 10.03*0.3891
= 1.12211649/3.902673
=0.2875
Fineness modulus=total sum of cumulative retained /1000
= 519.75/1000
=0.051975
1. Effective size of the soil (D10) = 10.03mm
2. Uniformly coefficient (Cu) = 0.0388
3. Coefficient of Curvature (Cc) = 0.2875
4. Fineness Modulus = 0.5198
Discussion and Conclusion
In this experiment, the plot of the graph of the data collected shows that the soil was
course grained soil with boulders, gravel, and sand particles according to the size distribution
depicted in the graph. The direction of the graph can also be used to predict the uniformity of the
grading of the soil. The data used in this experiment shows that the soil was well graded as it has
considerable soil mass proportions that are bigger than the majority as well as those that are
smaller than the majority (Das, 2015) p. 571)..
Consolidation Test
Introduction

Geotechnical Lab Report10
This test uses compressive loading on the soil sample, which leads to a decrease in the volume of
the soil as a result of the loading. In saturated conditions the soil when compressed undergoes a
reduction in the volume leads to the expelling of the water in the voids within the sample, as
water is incompressible. Consolidation thus occurs when the water in the pores of the soil sample
is expelled out as a result of this loading. This leads to an increase in the effective stress of the
sample increasing and thus the volume decreases. The rate of the water being expelled is related
to the permeability of the soil (Terzaghi & Peck, 2007).
Procedure
The sample was placed in the consolidometer, and dial gauges were incorporated to measure the
vertical loading. The mold was then filled with water and the readings taken.
Results
Height (mm)
Diameter (mm)
Area
Mass of Ring
Mass of specimen + ring
Moisture Content (%)
Bulk Density (Mg/m3)
Dry Density (Mg/m3)
Void Ratio
Degree of Saturation (%)
Specific Gravity of Soil - Gs
Date Time
Elapse
d time
(min)
Transduce
r Reading
(mm)
Elapsed Time
(root min)
Stage
Information
0.125
0.25
0.5
1
2
‘/9 4
8

Geotechnical Lab Report11
16
32
60
120
240
480
960
1440
Discussion
The rate at which the water is dispelled represents the permeability of the soil
Permeability Tests
Introduction
Permeability refers to the level of porosity which allows water to pass through or seep into the
soil through the voids. Its coefficients can be established through the falling and constant head
methods. In falling head the formula is given by
k =2.203 aL
At log h1
h 2
While the constant head coefficient is given by
k = QL
h ∆ T
(Das, 2015)
Procedure
The sample was prepared and the saturated. When the samples were placed in the oedometer, the
results were taken and recorded for both the falling head and constant head set ups.
Results
Falling head
Trial
No.
h0
(mm)
h1
(mm)
Time (s) k

Geotechnical Lab Report12
1 1399 999 2697
2 1399 999 2717.5
3 1399 999 2708
Water temperature = 21oC
Constant head
Trial
No.
H1
(mm)
H2
(mm)
H3
(mm)
Volum
e
(mm3)
Time
(s)
Q (mm3/s)
1 947 926 914 334100 25.34 13184.
7
334.1 g
2 947 926 914 315400 27.01 11677.
2
315.4 g
3 947 926 914 335900 27.46 12232.
3
335.9 g
4 978 963 952 339200 37.34 9084.0
9
339.2 g
5 978 963 952 338100 37.4 9040.1
1
338.1 g
6 978 963 952 344900 38.04 9066.7
7
344.9 g
7 962 942 928 354200 32.23 10989.
8
354.2 g
8 962 942 928 335900 30.13 11148.
4
335.9 g
9 962 942 928 347100 31.53 11008.
6
347.1 g
Discussion
The permeability of the sample was established in both methods.
References
Das, B., 2015. Principles of Geotechnical Engineering. 4th ed. BOston: PWS Publishers.

Geotechnical Lab Report13
Terzaghi, K. & Peck, R. B., 2007. Soil Mechanics in Engineering Practice. 10th ed. New YOrk:
John Wiley & Sons.