43C

Sub: Geotechnical Engineering

Topic : Three Phase System

MODULE-43C Origin of soils, soil classification, three-phase system, fundamental definitions, relationship and interrelationships, _________________________________________________________________________

(C) 61.9 % (D) 60.6 %

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

The water content at 25 blows is called Liquid limit. i.e 61.9 4.

(A) 65.3 (B) 20.9 (C) 83.7 (D) 54.4 0.65

0.544

0.2*2.72 1

2.72

2.

Data from a sieve analysis conducted on a given sample of soil showed that 67% of the particles passed through 75 micron IS sieve. The liquid limit and plastic limit of the finer fraction was found to be 45 and 33 percents respectively. The group symbol of the given soil as per IS: 1498-1970 is (A) SC

(B) MI

(C) CH

(D) MH

As more than 50 % of the total soil is finer than 75 the given soil is fine grained soil

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

CL

CI

ML

MI

CH H

12

(A) 100% (B) 75% (C) 50% (D) 25%

20

35

MH 50

on the A-line, =18.25 The soil is below A-line. So the soil is MI 3.

The following data were obtained from a liquid limit lest conducted on a soil sample. Number of blows Water content (%)

17

22

25

28

34

68.3

63.1

61.9

60.6

60.5

The liquid limit of the soil is (A) 63.1 % (B) 62.8 %

JH ACADEMY

5.

The undrained cohesion of a remoulded clay soil is 10 kN/m2. If the sensitivity of the clay is 20, the corresponding remoulded compressive strength is (a) 5 kN/m2 (b) 10 kN/m2 2 (c) 20 kN/m (d) 200 kN/m2 Compressive strength = 2C =20 kN/m2

6.

The ratio of saturated unit weight to dry unit weight of dry unit weight is 1.25. If the

Page 1

Sub: Geotechnical Engineering specific gravity of solids (Gs) is 2.65, the void ratio of the soil is (a) 0.625 (b) 0.663 (c) 0.944 (d) 1.325

e

e

2.56

1

Topic : Three Phase System

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.

CH H

CL

CI

ML

MI

22 e=0.663

20 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. Soil of higher proportion comes in last (a)

8.

A saturated soil mass has a total density 3 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.

35

MH 50

on the A-line, =14.6 The soil is above A-line. So the soil is clayey. The classification is SC 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

0.3*27

e

27

1

0.81

The bulk density is equal to saturated density as the soil is in saturated condition. 3 i.e 22 kN/m . 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 (C) Main soil symbol comes first 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 425μ sieves are 40% and 18% respectively. The soil may be classified as (a) SC (b) MI (c) CI (d) SM

JH ACADEMY

12. The liquid limit (LL), plastic limit (PL) and shrinkage limit (SL) of a cohesive soil satisfy the relation (A) LL>PLPL>SL (C) LL4 3. Soil have low plasticity 4. Soil have low compressibility Codes: A B C D a) 1 2 4 3 b) 2 1 3 4 c) 2 1 4 3 d) 1 2 3 4

Determination of shear parameters Determination of specific gravity Determination of bearing capacity Grain size distribution tests for clays

Codes :

a) b) c) d)

A

B

C

D

2 4 2 4

1 3 3 1

4 2 4 2

3 1 1 3

b) 72. In comparison to Atterberg limits of normal soils, the expansive soils have which of the fallowing? 1. More liquid limit 2. Less plastic limit 3. Less shrinkage limit 4. More volumetric shrinkage 5. Select the correct answer using the codes given below a)1,2,3 and 4

73. Consider the following statements: On additions of lime to swelling soils, Their liquid limit increases Their plastic limit increases Their shrinkage limit increases Their swelling potential decreases

JH ACADEMY

75. Match List-I (Soil ) with List-II ( Type) and select the correct answer using the codes given below the lists. List-I

List-II

A) Fine sand B) Silt C) Peat

1. Expansive .Soil 2. Coarse graines Soil 3. Fine grained 4. Organic soil

b) 1,3 and 4 only

c) 2 and 3 only d) 1, 2 and 4 only

1. 2. 3. 4.

c)

a) b) c) d)

Codes A B 3 2 4 3 3 1 2 3

C 1 2 2 4

d) 76. Match List-I(Symbol) with List-II( Soil) and select the correct answer using the codes given below the lists:

Page 12

Sub: Geotechnical Engineering

Topic : Three Phase System a) 0.25

List-I A. ML

b) 0.50 c) 0.75

d) 1.0

81. A specimen of clayey silt contains 70% silt size particles. Its liquid limit = 40. And plastic limit =20, In liquid limit test, at moisture content of 30%, required number of blows was 50. Its plasticity index, activity and consistency index will respectively be

B. SM C. Pt D. MH List-II

a) 20, 0.67 and 0.5

1. 2. 3. 4.

b) 20, 1.5 and 2.0

Silty sand Inorganic silt with large compressibility Inorganic silt with low compressibility Soil with high organic content with high compressibility

Codes: A

B

C

D

a)

3

2

4

1

b)

4

1

3

2

c)

3

1

4

2

d)

4

2

3

1

c) 30, 1.5 and 0.72 d) 20, 0.286 and 0.38 82. Match List-I (Measuring device) with List-II (Soil parameter) and select the correct answer using the codes given below the lists: List-I A. B. C. D.

list-II

Pycnometer Hydrometer Odometer Permeameter

1. Compressibility 2. Permeability 3. Specific gravity 4. Particle size analysis

Codes: c) 77. For a sandy soil with soil grains spherical in shape and uniform in size, what is the theoretical void ratio? a) 0.61

b) 0.71 c ) 0.91

d) 0.81

78. A soil has liquid limit=35, plastic limit=20, shrinkage limit=10 and natural moisture content=25%. What will be its liquidity index, plasticity index and shrinkage index? a) 0.67,15 and 25

b) 0.33,15 and 10

c) 0.67,25 and 15

d)0.33,20 and 15

a) b) c) d)

A

B C D

2 3 2 3

4 1 1 4

1 4 4 1

3 2 3 2

d) 83. Match List-I (Deposit) with List-II (Soil structure) and select the correct answer using the codes given below the lists: List-I

79. A cohesive soil yields a maximum dry density of 16 kN/m3 during a standard proctor Compaction test. If the specific gravity is 2.65, what would be its void ratio? a) 0.552

b) 0.624 c) 0.712

d) 0.583

80. 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

JH ACADEMY

A. B. C. D.

Coarse grained soil Silt deposit Clay deposit Composite soil

List-II 1. Flocculated 2. Cohesive matrix 3. Honeycomb 4. Single-grained

Codes: A B C D a) 2 3 1 4 b) 4 3 1 2 c) 2 1 3 4 d) 4 1 3 2

Page 13

Sub: Geotechnical Engineering

Topic : Three Phase System

b) 84. On analysis of particle size distribution of a soil, it is found that =0.1mm, =0.3mm and =0.8mm.The uniformity coefficient and coefficient of curvature, as given by the particle size distribution curve, are respectively. a) 3 and 3

b) 2.67 and 1.125

c) 2.67 and 3

d) 8 and 1.125

85. The natural water content of the soil sample was found to be 40%, specific gravity is 2.7 and void ratio 1.2; then the degree of saturation of the soil will be a) 100%

b) 69% c) 87%

d) 90%

86. The porosity of a soil sample having its void ratio equal to unity would be a) 33.34%

b) 50.0% c) 66.66%

d)75.0%

87. In a liquid limit test, the moisture content at 10 blows was 70% and that at 100 blows was 20%. The liquid limit of the soil is a) 35% b) 50% c) 65% d) 45% 88. A compacted soil sample using 10% moisture content has a weight of 200g and mass unit weight of 2.0g/cc. if the specific gravity of soil particles and water are 2.7 and 1.0, the degree of saturation of the soil is a) 11.1% b) 55.6% c) 69.6% d) 80% 89. Sieve analysis was carried out on a soil sample of 400gms. Out of 400gms, of soil 160gm retained on 4.75mm sieve, 120gm retained on 2mm sieve and 80gm retained on 600 sieve. The value of will be a). 7.4, 1.7 b) 1.7, 7.4 c) 7.92, 1.4 d)1.4, 7.92 90. Degree of saturation of a natural soil deposit having content 15% specific gravity 2.50 and void ratio 0.5 is a) 50% b) 60% c) 75% d) 80%

JH ACADEMY

91. The liquidity index is defined as a ratio expressed as percentage of a) Plastic limit minus natural water content, to its plasticity index b) Natural water content minus its plastic limit to its plasticity index c) Natural water content plus in elastic limit, to its plasticity index d) Liquid limit minus natural water content to the plasticity index. 92. The weight of a Pycnometer containing 400g sand and water full to the top is 2150gr. The weight of Pycnometer full of clean water is 1950g. if specific gravity of the soil is 2.5, the water content is a) 5% b) 10% c) 15% d) 20% 93. The unit weight of a soil at zero air voids depends on a) Specific gravity b) Water content c) Unit wt. of water d) All d) 94. Which one of the following relations is not correct? a) b) c) d) b) 95. If the porosity of soil sample is 20%, the void ratio is a) 0.20 b) 0.80 c) 1.00 d) 0.25 d) 96. Principle involved in relationship between submerged unit weight and saturated unit weight of soil is based on a) Equilibrium of floating bodies b) Archemedes principle c) Stokes’s law d) Darcy’s law b) 97. A soil sample has a void ratio 0.5 and porosity will be close to a) 50% b) 66% c) 100% d) 33% d)

Page 14

Sub: Geotechnical Engineering 98. A barrow pit soil has a dry density of 17KN/ . How many cubic meters of this soil will be required to construct an embankment of 100 volume with a dry density of 16KN/ a) 94 b) 106 c) 100

d) 90

99. The void ratio and specific gravity of a soil are 0.65 & 2.72 respectively. The degree of saturation (%) corresponding to water content of 20% is a) 65.3 b) 20.9 c) 83.7 d) 54.4 100. A saturated soil mass has a total density 22KN/ and water of 10%. The bulk density and dry density of the soil are a) 12KN/ and 20KN/ b) 22 &20KN/ c) 19.8 &19.8KN/ d) 23.2 & 19.8KN/ 101. The water content of saturated soil and the specific gravity of soil solids were found to be 30% and 2.7 respectively. Assuming the unit of water to be 10KN/ , the saturated unit weight (KN/ ) 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, 0.45 102. The saturated unit weight of the sand (KN/ ) is to be find for water content= 20%, G= 2.7 and =10KN/ a) 15 b) 18 c) 21 d) 24

Topic : Three Phase System d) 105. In this natural condition, a soil sample has a mass of 1.980kg and a volume of 0.001 . After being completely dried in an oven, the mass of sample is 1.8kg. Specific gravity G is 2.7. Unit weight of water is 10KN/ . The degree of saturation of the soil is a) 0.65 b) 0.70 c) 0.54 d) 0.61 106. The maximum possible value of group index for a soil is 20 . 107. The description sandy silty clay signifies that a) The soil contains unequal proportions of the three constituents in the order sand > silt > clay b) The soil contains equal proportions of sand, silt and clay c) The soil contains unequal proportions of three constituents such that clay>silt>sand d) There is no information regarding the relative proportions of the three c) 108. The Atterberg limits of clay are 38%, 27% and 24.5%. Its natural water content is 30%. The clay is in state. Plastic 109. A soil having particles of nearly the same size is known as a) Well graded b) Uniformly graded c) Poorly graded d) Gap graded b)

103. A saturated undistributed sample from a clay stratum has moisture content of 22.22% and specific weight is 2.7. assuming =10KN/ , the void ratio and saturated unit weight of clay respectively are a) 0.6 and 16.875KN/ b) 0.3 and 20.625KN/ c) 0.6 and 20.625KN/ d) 0.3 and 16.975KN/ 104. In a compaction test, G, W, S, and e represent the specific gravity, water content, degree of saturation and void ratio of the soil sample respectively. If represents unit weight of water and represents the dry unit weight of the soil, the equation for zero-air voids line is a) b) c)

=

JH ACADEMY

110. The consistency of saturated cohesive soil is affected by a) Water content b) Particle size distribution c) Density index d) Co-efficient of permeability a)

111. The equation of A-line in the plasticity chart is 112. The particle size distribution curves are extremely useful for the classification of a) Fine grained soils b) Coarse grained soils c) Both fine and coarse grained soils d) Silts and clays

Page 15

Sub: Geotechnical Engineering b) 113. Consistency index for a clay soil is a) b) c) LL-PL d) 0.5w a) 114. Some of the structural strength of a clayey material is lost by remolding is slowly recovered with time. This property of soils to undergo an isothermal gel-to-sol-to-gel transformation upon agitation and sub-sequent rest is termed a) Isotropy b) Anisotropy c) Thixotropy d) Allotropy 115. The values of liquid limit and plasticity index for soils having common geological origin in a restricted locality usually define a) A zone above A-line b) A straight line parallel to A-line c) A straight line perpendicular to A-line d) Points may be anywhere in the plasticity chart 116. Toughness index of a clayey soils is given by a) Plasticity index/flow index b) Liquid limit/plastic limit c) Liquidity index/plastic limit d) Plastic limit/ liquidity index 117. Soil has been compacted in an embankment at bulk density of 2.15Mg/ and a water content of 12%. The value of specific gravity of soil solids is 2.65. The water table is well below the foundation level. Estimate the dry density, void ratio, degree of saturation and air content of compacted soil. 118. The un drained cohesion of a remoulded clay soil is 10KN/ . If the sensivity of the clay is 20, the corresponding remoulded compressive strength is a) 5KN/ b) 10KN/ c)

20KN/

d) 200KN/

119. A soil mass contains 40% gravel, 50%sand & 10% silt. The soil can be classified as a) Silty sandy gravel having co-efficient of uniformity less than 60

JH ACADEMY

Topic : Three Phase System b) Silty gravelly sand having co-efficient of uniformity equal to 10 c) Gravelly silty sand having co-efficient of uniformity greater than 60 d) Gravelly silty sand and its coefficient of uniformity cannot be determined. a) 120. In a standard proctor test, 1.8kg of moist soil was filling the mould (volume=944Cc) after compaction. A soil sample weighing 23g was taken from mould and over dried for 24 hours at a temperature of C weight of the dry sample was found to be 20g. Specific gravity of soil solids is a=2.7. the theoretical maximum value of the dry unit weight of the soil at that water content is equal to a) 4.67KN/ b) 11.5KN/ c) 16.26KN/

d) 18.85KN/

121. Laboratory sieve analysis was carried out on a soil sample using complete set of standard IS sieves. Out of 500gr. Of soil used in the test, 200g was retained on IS-600 size, 250g was retained on IS-500 sieve and remaining 50g was retained on IS-425 sieve a) The Coefficient of uniformity of soil is a. 0.9 b. 1.0 c. 1.1 d. 1.2 As 60 % of particles passed on 600 size and 10 % particles passed on 500 , .

b) The classification of soil is a. SP b. SW c. CI d. GW As the particles are in between 75 and 4.75 mm, it is classified as sand and as is not more than 6, it is poorly graded. So it is SP.

122. Group symbols to silty sand and clayey sand are respectively a) SS and CS b) SM and CS c) SM and SC d) MS and CS c)

Page 16

Sub: Geotechnical Engineering 123. 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