CL137 Paper B: Soil Mechanics
Answer Book
Student Number 202132268
Answers to Q.1
BS sieve size
% retained
% passing
3.35 mm
0
100
2.0 mm
0.9
99.1
1.18 mm
2.8
96.3
600 m
8.1
88.2
425 m
13.4
74.8
300 m
24.7
50.1
212 m
24.9
25.2
150 m
18.0
7.2
63 m
6.9
0.3
<63 m
-
0.3
Worksheet Q.1(a). Particle Size Test Data
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Worksheet Q.1(b). Particle size distribution chart
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Answers to Q.1
Write Calculations and Answer Below
Q.1(b)
Coefficient of
Uniformity, Cu
=0.41/0.2 = 2.05
Q.1(b)
Coefficient of
Curvature, Cz
= 0.3^2/0.2*0.41= 1.1
Q.1(b)
Classification
of Soil
99.1% sand, 0.9% gravel. This soil classifies
as slightly gravely sand. SSG
Worksheet Q.1(c). Soil Classification
Q2 a)
Q2 b)
CL137
Based on the assumption that large,
heavy particles settle more quickly in
water, determine the relative proportions
of sand, silt, and clay in a soil sample.
Fill the jar halfway with soil sample. 1
and a half cups distilled water are then
added. Cover the container and shake
vigorously. measure the depth of the
settled soil after a period. Shake the jar
again well, the record the depth of sand
at the top. Do the same again and
measure for silt depth and repat again
and measure for clay depth. Once all
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the results have been recorded a
grading curve can be plotted
Q2 c) (i)
(ii)
(iii)
(iv)
CL137
W = m-ms = 1876-1524/1524 =
23%
=mg/v =(1.876 *9.810)/0.001 =
18.4Knm3
e = (V-Vs)/Vs = 0.001 –
0.000569/0.000569 = 0.76
Vs = ms/ GsPw = 1.524/2.68*1000
= 5.69*10-4m3
Sr = wGS/e = 0.23*2.68/0.75 =
81%
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Answers to Q.3
Test No.
Mass of soil (g)
Water content (%)
Bulk density,  (kg/m3)
1
1872
6.5
1872
2
1966
8.7
1966
3
2043
10.6
2043
4
2068
12.2
2068
5
1996
14.4
1996
Dry density, d (kg/m3)
1758
1809
1847
1843
1745
Write Calculations Below
Q.3(ii)
Bulk density & dry density (kg/m3)
1) P= 1.872/ 1000x 10-6 = 1872 Kg/m3
Pd = 1872/ 1 +0.065 = 1758 Kg/m3
2) P = 1.966/ 1000x 10-6 = 1966 Kg/m3
Pd = 1966/ 1 + 0.087 = 1809 Kg/m3
3) P = 2.043/ 1000x 10-6 = 2043 Kg/m3
Pd = 2043/ 1 + 1.06 = 1847 Kg/m3
4) P = 2.068/ 1000x 10-6 = 2068 Kg/m3
Pd = 2068/ 1 + 1.22 = 1843 Kg/m3
5) P = 1.996/ 1000x 10-6 = 1996 Kg/m3
Pd = 1996/ 1 +1.44 = 1745 Kg/m3
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Worksheet Q.3. Calculations & Answers
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Water Content (%)_
1900
1890
1880
1870
1860
Dry Density (Kg/m3)
1850
1840
1830
1820
1810
1800
1790
1780
1770
1760
1750
1740
6
8
10
00
12
14
16
18
Water Content(%)
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Q4 a)
Q4 b)
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Answers to Q.3
Write Calculations and Answers Below
Q.3(a)
Optimum water content (%) and maximum dry density (kg/m 3)
Wopt = 11%
Max Dry density =1848 Kg/m3
Q.3(b)
0% air voids calculations
1847 = (2.6(1-Ar)/1+0.11*2.6) *1000
Ar = 8.64%
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Worksheet Q.3. Calculations & Answers
Answers to Q.4 use your main document
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