Soil Mechanics JH Academy Question PDF
Soil Mechanics JH Academy Question PDF
Soil Mechanics JH Academy Question PDF
MODULE-43C
Origin of soils, soil classification, three-phase system, fundamental definitions,
relationship and interrelationships,
_________________________________________________________________________
1. The void ratio and specific gravity of a soil are 0.65 and 2.72
respectively. The degree of saturation (in percent) corresponding
to water content of 20% is
Ans:
0.65
0.544
0.2*2.72
2.72 1
2. The avoid ratios at the densest, loosest and the natural states of a sand
deposit are 0.2, 0.6 and 0.4, respectively. The relative density of the
deposit is
Ans:
3. The following data were obtained from a liquid limit lest conducted on
a soil sample.
Number 17 22 25 28 34
of blows
Water 68.3 63.1 61.9 60.6 60.5
content
(%)
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Sub: Geotechnical Engineering Topic : Three Phase System
Ans:
The water content at 25 blows is called Liquid
limit. i.e. 61.9
(A) SC (B) MI
(C) CH (D) MH
Ans:
As more than 50 % of the total soil is finer than 75 the given soil is
fine grained soil
CL CI CH
12 H
ML MI MH
20 35 50
Ans:
6. The ratio of saturated unit weight to dry unit weight of dry unit weight
is 1.25. If the specific gravity of solids (G s) is 2.65, the void ratio of the
soil is
(a) 0.625 (b) 0.663
(c) 0.944 (d) 1.325
Ans:
e e
2.65 1
e=0.663
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7. A soil mass contains 40% gravel, 50% sand and 10% silt. This soil can
be classified as
(a) silty sandy gravel having coefficient of uniformity less than
60.
(b) silty gravelly sand having coefficient of uniformity equal to
10.
(c) gravelly silty sand having coefficient of uniformity greater than
60.
(d) gravelly silty sand and its coefficient of uniformity cannot be
determined.
Ans:
Soil of higher proportion comes in last
3
8. A saturated soil mass has a total density 22kN/m and a water content
of 10%. The bulk density and dry density of this soil are
3 3
(a) 12 kN/m and 20 kN/m respectively.
3 3
(b) 22 kN/m and 20 kN/m respectively.
3 3
(c) 19.8kN/m and19.8 N/m respectively.
3 3
(d) 23.2kN/m and19.8kN/m respectively.
Ans:
The bulk density is equal to saturated density as the soil is in saturated
3
condition. i.e 22 kN/m .
9. Sieve analysis on a dry soil sample of mass 1000 g showed that 980 g
and 270 g of soil pass through 4.75 mm and 0.075 mm sieve,
respectively. The liquid limit and plastic limits of the soil fraction
passing through 425 sieves are 40% and 18% respectively. The soil
may be classified as
(a) SC (b) MI (c) CI (d) SM
Ans:
As 270 gm out of 1000gm pass through 75 sieve, the soil should be
coarse grained. The remaining 730 gm of soil, the gravel is only 20 gm
and 710 gm is sand. The sand fraction is more than gravel. So the soil
should be sand. The percentage of fines is 27 %, which is more than 12
%. So we need to get information from A-line.
CL CI CH
H
22
ML MI MH
20 35 50
The classification is SC
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10. The water content of a saturated soil and the specific gravity of soil
solids were found to be 30% and 2.70, respectively. Assuming the unit
weight of water to be 10 kN/m3, the saturated unit weight (kN/m3) and
the void ratio of the soil are
(a) 19.4, 0.81 (b) 18.5, 0.30
(c) 19.4, 0.45 (d) 18.5, 0.45
Ans:
0.3*27 e 0.81
27 1
11. Group symbols assigned to silty sand and clayey sand are respectively
(A) SS and CS (B) SM and CS
(C) SM and SC (D) MS and CS
Ans:
Main soil symbol comes first
12. The liquid limit (LL), plastic limit (PL) and shrinkage limit (SL) of a
cohesive soil satisfy the relation
(A) LL>PL<SL (B) LL>PL>SL
(C) LL<PL<SL (D) LL<PL>SL
Ans:
volume
Water content
14. The laboratory test results of a soil sample are given below:
Percentage finer than 4.75 mm = 60
Percentage finer than 0.075 mm = 30
Liquid Limit = 35%
Plastic Limit = 27%
The soil classification is
(A) GM (B) SM (C) GC (D) ML-MI
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Ans:
Coarse fraction =70
Fine fraction =30
As coarse fraction is more than fines, the soil is coarse grained.
Gravel=40 and sand =30.
So the soil is gravel.
As fines are more than 12%, we need to check A-line.
CL CI CH
H
ML MI MH
20 35 50
The classification is GM
(A) (B)
(C) (D)
Ans:
wG e wG
16. A fine grained soil has liquid limit of 60 and plastic limit of 20. As per
the plasticity chart. according to IS classification, the soil is represented
by the letter symbols
(A)CL (B)CI (C) CH (D) CL-ML
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Ans:
CL CI CH
40 H
ML MI MH
20 35 50
The classification is CH
17. The results for sieve analysis carried out for three types of sand, P, Q
and R, are given in the adjoining figure. If the fineness modulus values
of the three sands are given as , it can be stated
that
(A)
(B)
(C)
(D)
Ans:
Area under the curve represents fineness modulus.
18. As per the Indian Standard soil classification system, a sample of silty
clay with liquid limit of 40% and plasticity index of 28% is classified as
(A) CH (B) CI (C) CL (D) CL-ML
Ans:
A line equation, =14.6
The soil is above A-line and it is intermediate compressibility. So it is
CI
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19. In its natural condition, a soil sample has a mass of 1.980 and a
volume of 0.001 . After being completely dried in an oven, the mass
of the sample is 1.800 . Specific gravity is 2.7. Unit weight of
water is 10 . The degree of saturation of the soil is:
(A) 0.65 (B) 0.70 (C) 0.54 (D) 0.61
Ans:
e
0.27
0.1*27
27 1
20. Match list-I (type of soil) with list-II (mode of transportation and
deposition) and select the correct answer using the codes given below
the lists:
List I
A. Lacustrine soils
B. Alluvial soils
C. Aeolian soils
D. Marine soils
List-II
1. Transportation by wind
2. Transportation by running water
3. Deposited at the bottom of lakes
4. Deposited in sea water
Codes:
A B C D
a. 1 2 3 4
b. 3 2 1 4
c. 3 2 4 1
d. 1 3 2 4
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Ans:
(b)
21. The liquid limit and plastic limit of samples are 65% and 29%
respectively. The percentage of soil fraction with grain size finger than
0.002 mm is 24. The activity ratio of the soil sample is
(a) 0.05 (b) 1.00 (c) 1.50 (d) 2.00
Ans:
22. A soil sample as shrinkage limit of 10% and specific gravity soils as
2.7. The porosity of the soil at shrinkage limit is
Ans:
0.1*2.7 e=0.27
=0.212
23. In a wet soil mass, air occupies one-sixth of its volume and water
occupies one-third of its volume. The void ratio of the soil is
Ans:
1/6
1/3
0.5
Ans:
(d)
25. The standard plasticity chart to classify fine grained soils is shown in
the given figure
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Ans:
(d)
26. A soil sample is having a specific gravity of 2.60 and a void ratio of
0.78. The water content in percentage required to fully saturate the soil
at that void ratio would be
Ans:
0.78 e=0.78
= 0.3
27. A dry soil has mass specific gravity of 1.35. If the specific gravity of
solids is 2.7, Then the void ratio will be
Ans:
2.7 1
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28. A clay sample has a void ratio of 0.50 in dry state and specific gravity
of solids = 2.70. Its shrinkage limit will be
Ans:
Shrinkage limit is nothing but water content at just saturated state.
0.5 e 0.5
2.7 1
29. A soil has liquid limit of 60% plastic limit of 35% and shrinkage limit
of 20% and it has a natural moisture content of 50%. The liquidity
index of soil is
Ans:
volume
Water content
a) 1, 2 and 3 b) 1, 3 and 4
c) 2, 3 and 4 d) 1, 2 and 4
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Ans:
1.5
31. A soil has a liquid limit of 45% and lies above the A-line when plotted
on a plasticity chart. The group symbol of the soil as per IS soil
classification is
Ans:
(b)
32. The dry density of a soil is 1.5 g/cc. If the saturation water content were
50% then its saturated density and submerged density would,
respectively, be
Ans:
=1.5*(1+0.5)=2.25 g/cc
=2.25-1=1.25
Ans:
Mass of solids of fill =
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1. Shrinkage limit
2.Plastic limit
3.Liquid limit
Ans: (b)
35. Given the Plasticity Index (PI) of a local soil =15 and PI of sand=Zero,
for a described PI of 6, the percentage of sand in the mix should be
Ans:
Ans: (c)
37. A Clayey soil has Liquid limit = , Plastic limit = and natural
moisture content = . The consistency index of the soil is given by
(a) (b)
( ) ( )
(c) ) (d) )
Ans: (a)
38. A soil has mass unit weight , water content w (as ratio). The specific
gravity of soil soilds = G, unit weight of water= ; S is the degree of
saturation of the soil is given by
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Sub: Geotechnical Engineering Topic : Three Phase System
(a) S =
(b) S =
(c) S =
(d) S =
Ans:
e
wG wG
G 1
39. The saturated and dry densities of a soil are respectively 2000kg/m and
1500 kg/m. The water content (in percentage) of the soil in the
saturated state would be
Ans:
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Ans:
Mass of solids=1600*10=0.16 kg
Existing water=0.18-0.16=0.02 kg
Water content=0.04/0.16=0.25
41. Match List-I (terms) with List-II (formulae) and select the correct
answer using the codes given below this list
List-I List-II
A. Void ratio 1.
B. Porosity 2.
C. Degree of saturation 3.
D. Water content 4.
5.
Codes
A B C D
(a) 4 3 5 1
(b) 5 4 3 1
(c) 4 1 5 2
(d) 5 1 3 2
Ans: (d)
42. If an unconfined compressive strength of 4 kg/cm in the natural state of
clay reduces by four times in the remoulded state, then its sensivity will
be
Ans: (c)
43. If the proportion of soil passing 75 micron sieve is 50% and the liquid
limit and plastic limit are 40% and 20% respectively, then the group
index of the soil is
Ans: (b)
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44. Match List-I with List-II and select the correct answer using the codes
given below the list List-I
A) Loess
B) Peat
C) Alluvial soil
D) Marl
List-II
1. Deposited from suspension in running water
2. deposits of marine origin
3. deposits of wind
4. organic soil
CODES:
A B C D
a) 3 4 2 1
b) 4 3 1 2
c) 4 3 2 1
d) 3 4 1 2
Ans: (d)
45. Match List-I (soils) with List-II (group symbols) and select the correct
answer using codes given below the lists
List-I
A. Clayey gravel
B. Clayey sand
C. Organic clay
D. Silty sand
List-II
1. SM
2. OH
3. SC
4. GC
CODES:
A B C D
a) 3 4 2 1
b) 4 3 1 2
c) 4 3 2 1
d) 3 4 1 2
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Ans: (c)
46. The value of porosity of a soil sample in which the total volume of soil
grains is equal to twice the total volume of voids would be
Ans: (c)
47. A soil has a liquid limit of 40% and plasticity index of 20% the plastic
limit of the soil will be
Ans: (a)
48. A sample of saturated sand has a dry unit weight of 18 KN/m3 and a
specific gravity of 2.7. If density of water 10KN/m3, the void ratio of
the soil sample will be
Ans:
27 1
49. A dry soil sample has equal amounts of soils and voids of volume. Its
void ratio and porosity will be
a) 1.0 100%
b) 0.5 50%
c) 0.5 100%
d)1.0 50%
Ans: (d)
50. Based on grain distribution analysis, The D10, D30 and D60 values of a
given soil are 0.23mm, 0.3mm and 0.41mm respectively. As per IS
code, the soil classification will be
a) SW b) SP c) SM d) SC
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Ans:
The given soil is of size less than 4.75 mm and more than 75 . So the
soil is sand
51. The plasticity index and the percentage of grain size finer than 2
microns of a clay sample of 25 and 15 respectively. Its activity ratio is
Ans:
52. A soil sample having a void ratio of 1.3, water content of 50% and a
specific gravity 2.60 is in a state of
Ans:
53. The natural void ratio of sand sample is 0.6 and its density index is 0.6.
If its void ratio in the loosest state is 0.9, then the void ratio in the
densest state will be
Ans:
54. Which one of the following phase diagrams represents a clay at its
shrinkage limit?
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Ans: (b)
55. Which one of the following correctly represents the dry unit weight of a
soil sample which has a bulk unit weight of at a moisture content of
w%?
a) c)
b) ] d)
Ans: (c)
56. Given that the coefficient of curvature = 1.4 D30 = 3mm, D10 = 0.6mm,
based on this information of particle size distribution for use as a sub
grade, this soil will be taken to be
b) Well-graded sand
d) Poorly-graded sand
Ans:
57. Which one of the following represents relative density of saturated sand
deposit having moisture content of 25% if maximum and minimum
void ratio of sand are 0.95 and 0.45 respectively and specific gravity of
sand particles is 2.6?
Ans:
0.65 0.65
2.6 1
58. In a soil specimen, 70% particles are passing through 4.75mm IS sieve
and 40% particles are passing through 75 IS sieve. Its uniformity
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a) SP b) GP c ) SW d) GW
Ans: (c)
Ans: (a)
60. The predominant mineral responsible for shrinkage and swelling in
black cotton soils is
a) illite b) kaolinite
c) mica d) montmorillonite
Ans: (d)
Ans: (b)
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Ans:
volume
Water content
63. Two soil sample A and B have porosities =40% and =60%
respectively. What is the ratio of void ratios eA :eB?
64. Match List-I (densities) with List-II (expressions) and select the
correct answer using the codes given below the lists:
(Symbols G, e, w and S stand for specific gravity of a soil grains ,
void ratio, unit weight of water and degree of saturation respectively)
List-I List-II
a) Dry density 1) w (G+Se)/(1+e)
A B C D
a) 2 1 4 3
b) 2 3 4 1
c) 4 1 2 3
d) 4 3 2 1
Ans: (a)
65. What are the respective values of void ratio , porosity ratio and
saturated density (in KN/m) for a soil sample which has saturation
moisture content of 20% and specific gravity of grains has 2.6? ( taken
density of water has 10KN/ m).
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Ans:
5.2 0.52
26 1
a) 14 b)18 c) 20 d) 23
Ans:
67. A clay sample has a void ratio 0.54 in dry state. the specific gravity of
soil solids is 2.7. what is the shrinkage limit of soil?
Ans:
5.4 0. 54
2.7 1
Ans: (d)
69. Which of the following relation gives the value of degree of saturation
S, in terms of unit Weight , water content w (as ratio) and specific
gravity of soil solids Gs is unit weight of the water?
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a)
b)
c)
d)
Ans: (c)
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