GATE SOLVED PAPER -CE

GATE SOLVED PAPER - CE GEOTECHNICAL ENGINEERING

YEAR 2013 Q. 1

ONE MARK

In its natural condition a soil sample has a mass of 1.980 kg and a volume of 0.001 m3 . After being completely dried in an oven; the mass of the sample is 1.800 kg . Specific gravity is 2.7. Unit weight of water is 10 kN/m3 . The degree of saturation of soil is (A) 0.65 (B) 0.7 (C) 0.54 (D) 0.61

Q. 2

Following statement are made on compacted soil, where DS stands for soil compaction on Dry side of OMC and WS stands for soil compacted on Wet Side of OMC. Identify incorrect statement (A) Soil structure is flocculated on DS and dispersed on WS. (B) Construction of pore water pressure is low on DS and High on WS (C) Soil on drying, shrinkage is high on DS and Low on WS (D) On addition to water, swelling is high on DS and low on WS.

Q. 3

The ratio N f /N d is known as shape-factor where N f is the number of flow channels and N d is the equipotential drop. The flownet always drawn with a constant b/a ratio where b and a are distance between two consecutive flow lines and equipotential lines respectively. Assuming that b/a ratio remains same, the shape factor of a flow net will change if the (A) upstream and downstream heads are interchanged. (B) soil in the flow space is changed (C) dimension of the flow space are changed (D) head difference causing the flow is changed

Q. 4

Four columns of building are to be located within a plot size of 10 m # 10 m . The expected load on each column is 4000 kN. Allowable bearing capacity of soil deposit is 100 kN/m2 . The type of foundation to be used is (A) Isolated foundation (B) Raft foundation (C) Pile foundation (D) Combined foundation

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GATE SOLVED PAPER - CE

GEOTECHNICAL ENGINEERING

YEAR 2013 Q. 5

TWO MARKS

The soil profile below a lake with water level at elevation = 0 m and lake bottom at elevation =- 10 m is shown in the figure, where k is the permeability coefficient. A piezometer (stand pipe) installed in the sand layer shows a reading of + 10 m elevation. Assume that the piezometric head is uniform in the sand layer. The quantity of water (in m3 /s ) flowing into the lake from the sand layer through the silt layer per unit area of the lake bed is

(A) 1.5 # 10-6 (C) 1.0 # 10-6

(B) 2.0 # 10-6 (D) 0.5 # 10-6

Q. 6

Laplace equation for water flow in soil is given by 22H + 22H + 22H = 0 2x2 2y2 2z2 Head H does not vary in y and z -direction. Boundary condition x = 0 , H = 5 m , dH =- 1. What is the value of H at x = 1.2 ? dx

Q. 7

Two soil profile are used as backfill behind a retaining wall as shown in the figure, where g t is total unit weight and c' & f' are effective shear parameters. Find the resultant active earth pressure in kN/m

(A) 31.7 (C) 57.8 Q. 8

The soil profile above the rock surface at 25º infinite slope is shown in figure where Su is undrain shear stress and g t is total unit weight. The slip will occur at a depth of

(A) 8.83 m (C) 7.83 m

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(B) 35.2 (D) 57

(B) 9.79 m (D) 6.53 m



Statement for Linked Q. 9 and 10 : A multistorey building with a basement is to be constructed, the top 4 m contains loose silt below which dense sand layer is present upto a great depth. Ground water table is at the ground surface. The foundation consists of the basement slab of 6 m width which will rest on the top of dense sand as shown in figure. For dense sand saturated unit weight is 20 kN/m3 and bearing capacity factor N q = 40 , N g = 45 , for loose silt saturated unit weight = 18 kN/m3 , N q = 15 , N g = 20 . Effective cohesion 0. Neglect depth factor average elastic modulus E , and Poisson ratio m of dense sand is 60 # 103 kN/m2 and 0.3 respectively, using factor of safety = 3 . (Take influence factor = 2 ) Q. 9

Q. 10

The net safe bearing capacity (in kN/m2) of foundation is

(A) 610

(B) 320

(C) 980

(D) 693

The immediate settlement of foundation is (A) 58 mm (B) 111 mm (C) 178 mm (D) 126 mm YEAR 2012

ONE MARK

Q. 11

The effective stress friction angle of a saturated, cohesionless soil is 38c. The ratio of shear stress to normal effective stress on the failure plane is (A) 0.781 (B) 0.616 (C) 0.488 (D) 0.438

Q. 12

Two series of compaction tests were performed in the laboratory on an inorganic clayey soil employing two different level of compaction energy per unit volume of soil. With regard to the above tests, the following two statements are made I. The optimum moisture content is expected to be more for the tests with higher energy. II. The maximum dry density is expected to be more for the tests with higher energy. The CORRECT option evaluating the above statement is (A) Only I is TRUE (B) Only II is TRUE (C) Both I and II are TRUE (D) Neither I nor II is TRUE

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Q. 13

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

Q. 14


(D) CL-ML

A smooth rigid retaining wall moves as shown in the sketch causing the backfill material to fail. The backfill material is homogenous and isotropic and obeys the Mohr-Coulomb failure criterion. The major principle stress is

(A) parallel to the wall face and acting downwards (B) normal to the wall face (C) oblique to the wall force acting downwards (D) oblique to the wall face acting upwards Q. 15

An embankment is to be constructed with a granular soil (bulk unit weight = 20 kN/m2 ) on a saturated clayey slit deposit (undrained shear strength = 25 kPa). Assuming undrained general shear failure and bearing capacity factor of 5.7. The maximum height (in m) of the embankment at the point of failure is (A) 7.1 (B) 5.0 (C) 4.5 (D) 2.5 YEAR 2012

TWO MARKS

Q. 16

Two soil specimens with identical geometric dimensions were subjects to falling head permeability tests in the laboratory under identical conditions. The fall of water head was measured after an identical time interval. The ratio of initial to final water heads for the test involving the first specimen was 1.25. If the coefficient of permeability of the second specimen in 5 times that of the first, the ratio of initial to final water heads in the test involving the second specimen is (A) 3.05 (B) 3.80 (C) 4.00 (D) 6.25

Q. 17

A layer of normally consolidated, saturated silty clay of 1 m thickness a is subject to one dimensional consolidation under a pressure increment of 20 kPa. The properties of the soil are : specific gravity = 2.7 , natural moisture content = 45% , compression index = 0.45 , and recompression index = 0.05 . The initial average effective stress within the layer is 100 kPa. Assuming Terzaghi’s theory to be applicable, the primary consolidation settlement (rounded off to nearest mm) is (A) 2 mm (B) 9 mm (C) 14 mm (D) 16 mm

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Steady state seepage is taking place through a soil element at Q , 2 m below the ground surface immediately downstream of the toe of an earthen dam as shown in the sketch. The water level in a piezometer installed at P , 500 mm above Q , is at the ground surface. The water level in a piezometer installed at R, 500 mm below Q , is 100 mm above the ground surface. The bulk saturated unit weight of the soil is 18 kN/m3 and the unit weight of water is 9.81 kN/m3 . The vertical effective stress (in kPa) at Q is

Q. 18

(A) 14.42 (C) 16.38

(B) 15.89 (D) 18.34

Common Data For Q. 19 and 20 : The flow net around a sheet pile wall is shown in the sketch. The properties of the soil are permeability coefficient = 0.09 m/day (isotropic), specific gravity = 2.70 and void ratio = 0.85 . The sheet pile wall and the bottom of the soil are impermeable.

Q. 19

The seepage loss (in m3 per day per unit length of the wall) of water is (A) 0.33 (B) 0.38 (C) 0.43 (D) 0.54

Q. 20

The factor of safety against the occurrence of piping failure is (A) 3.55 (B) 15.89 (C) 2.60 (D) 0.39

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YEAR 2011

ONE MARK

Q. 21

For a saturated sand deposit, the void ratio and the specific gravity of solids are 0.70 and 2.67, respectively. The critical (upward) hydraulic gradient for the deposit would be (A) 0.54 (B) 0.98 (C) 1.02 (D) 1.87

Q. 22

Likelihood of general shear failure for an isolated footing in sand decreases with (A) decreasing footing depth (B) decreasing inter-granular packing of the sand (C) increasing footing width (D) decreasing solid grain compressibility

Q. 23

For a sample of dry, cohesionless soil with firction angle, f, the failure plane will be inclined to the major principal plane by an angle equal to (A) f (B) 45c (C) 45c - f/2 (D) 45c + f/2

Q. 24

Two geometrically identical isolated footings, X (linear elastic) and Y (rigid), are loaded identically (shown alongside). The soil reactions will

(A) (B) (C) (D) Q. 25

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be uniformly distributed for Y but not for X be uniformly distributed for X but not for Y be uniformly distributed for both X and Y not be uniformly distributed for both X and Y

A soil is composed of solid spherical grains of identical specific gravity and diameter between 0.075 mm and 0.0075 mm. If the terminal velocity of the largest particle falling through water without flocculation is 0.5 mm/s, that for the smallest particle would be (A) 0.005 mm/s (B) 0.05 mm/s (C) 5 mm/s (D) 50 mm/s



TWO MARKS

YEAR 2011 Q. 26

Q. 27

A single under-reamed, 8 m long, RCC pile (shown in the adjoining figure) weighing 20 kN with 350 mm shaft diameter and 750 mm under ream diameter is installed within shiff, saturated silty clay (undrained shear strength is 50 kPa, adhesion factor is 0.3, and the applicable bearing capacity factor is 9) to counteract the impact of soil swelling on a structure constructed above. Neglecting suction and the contribution of the under-ream to the adhesive shaft capacity, what would be the estimated ultimate tensile capacity (rounded off to the nearest integer value of kN) of the pile ?

(A) 132 kN

(B) 156 kN

(C) 287 kN

(D) 301 kN

Identical surcharges are placed at ground surface at sites X and Y , with soil conditions shown alongside and water table at ground surface. The silty clay layers at X and Y are identical. The thin sand layer at Y is continuous and freedraining with a very large discharge capacity. If primary consolidation at X is estimated to complete in 36 months, what would be the corresponding time for completion of primary consolidation at Y ?

(A) 2.25 months (C) 9 months

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(B) 4.5 months (D) 36 months



A field vane shear testing instrument (shown alongside) was inserted completely into a deposit of soft, saturated silty clay with the vane rod vertical such that the top of the blades were 500 mm below the ground surface. Upon application of a rapidly increasing torque about the vane rod, the soil was found to fail when the torque reached 4.6 N-m. Assuming mobilization of undrained shear strength on all failure surfaces to be uniform and the resistance mobilized on the surface of the vane rod to be negligible, what would be the peak undrained shear strength (rounded off to the nearest integer value of kPa) of the soil ?

Q. 28

(A) 5 kPa

(B) 10 kPa

(C) 15 kPa

(D) 20 kPa

Common Data For Q. 29 and 30 : A sand layer found at sea floor under 20 m water depth is characterised with relative density = 40% , maximum void ratio = 1.0 , minimum void ratio = 0.5 , and specific gravity of soil solids = 2.67 . Assume the specific gravity of sea water to be 1.03 and the unit weight of fresh water to be 9.81 kN/m3 . Q. 29

What would be the effective stress (rounded off to the nearest integer value of kPa) at 30 m depth into the sand layer ? (A) 77 kPa (B) 273 kPa (C) 268 kPa (D) 281 kPa

Q. 30

What would be the change in the effective stress (rounded off to the nearest integer value of kPa) at 30 m depth into the sand layer if the sea water level permanently rises by 2 m ? (A) 19 kPa (B) 0 kPa (C) 21 kPa (D) 22 kPa YEAR 2010

Q. 31

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ONE MARK

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 gw represents the unit weight of water and gd represents the dry unit weight of the soil, the equation for zero air voids line is Ggw Ggw (B) gd = (A) gd = 1 + Gw 1 + Se (C) gd = Gw (D) gd = Gw 1 + gw S 1 + Se


Q. 32


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

Q. 33

Quick sand condition occurs when (A) the void ratio of the soil becomes 1.0 (B) the upward seepage pressure in soil becomes zero (C) the upward seepage pressure in soil becomes equal to the saturated unit weight of the soil (D) the upward seepage pressure in soil becomes equal to the submerged unit weight of the soil

Q. 34

The e -log p curve shown in the figure is representative of

(A) Normally consolidated clay (B) Over consolidated clay (C) Under consolidated clay (D) Normally consolidated clayey sand Q. 35

If sh , sv , shl and svl represent the total horizontal stress, total vertical stress, effective horizontal stress and effective vertical stress on a soil element, respectively, the coefficient of earth pressure at test is given by (A) sh sv (B) shl svl (C) sv sh (D) svl shl YEAR 2010

Q. 36

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TWO MARKS

The vertical stress at point P1 due to the point load Q on the ground surface as shown in figure is sz . According to Boussinesq’s equation, the vertical stress at point P2 shown in figure will be


(A) sz /2 (C) 2sz


(B) sz (D 4sz

Q. 37

An open ended steel barrel of 1 m height and 1 m diameter is filled with saturated fine sand having coefficient of permeability of 10-2 m/s . The barrel stands on a saturated bed of gravel. The time required for the water level in the barrel to drop by 0.75 m is (A) 58.9 s (B) 75 s (C) 100 s (D) 150 s

Q. 38

The ultimate load capacity of a 10 m long concrete pile of square cross section 500 mm # 500 mm driven into a homogeneous clay layer having undrained cohesion value of 40 kPa is 700 kN. If the cross section of the pile is reduced to 250 mm # 250 mm and the legth of the pile is increased to 20 m, the ultimate load capacity will be (A) 350 kN (B) 632.5 kN (C) 722.5 kN

(D) 1400 kN

A well of diameter 20 cm fully penetrates a confined aquifer. After a long period of pumping at a rate of 2720 litres per minutes the observations of drawdown taken at 10 m and 100 m distance from the centre of the well are found to be 3 m and 0.5 m respectively. The transmissivity of the aquifer is (A) 676 m2 /day (B) 576 m2 /day (C) 526 m2 /day (D) 249 m2 /day

Q. 39

Statement for Linked Q. 40 and 41 : The unconfined compressive strength of a saturated clay sample is 54 kPa. Q. 40

Q. 41

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The value of cohension for the clay is (A) zero (C) 27 kPa

(B) 13.5 kPa (D) 54 kPa

If a square footing of size 4 m # 4 m is resting on the surface of a deposit of the above clay, the ultimate bearing capacity of the footing (as per Terzaghi’s equation) is (A) 1600 kPa (B) 316 kPa (C) 200 kPa (D) 100 kPa



ONE MARK

YEAR 2009 Q. 42

Deposit with flocculated structure is formed when (A) clay particles settle on sea bed (B) clay particles settle on fresh water lake bed (C) sand particles settle on river bed (D) sand particles on sea bed

Q. 43

Dilatancy correction is required when a strata is (A) cohesive and saturated and also has N value of SPT > 15 (B) saturated silt/fine sand and N value of SPT < 15 after the overburden correction (C) saturated silt/fine sand and N value of SPT > 15 after the overburden correction (D) coarse sand under dry condition and N value of SPT < 10 after the overburden correction

Q. 44

A precast concrete pile is driven with a 50 kN hammer railing through a height of 1.0 m with an efficiency of 0.6. The set value observed is 4 mm per below and the combined temporary compression of the pile, cushion and the ground is 6 mm. As per Modified Hiley Formula, the ultimate resistance of the pile is (A) 3000 kN (B) 4285.7 kN (C) 8333 kN

Q. 45

(D) 11905 kN

The relationship among specific yield (Sy), specific retention (Sr ) and porosity (h) of an aquifer is (A) Sy = Sr + h (B) Sy = Sr - h (D) Sy = Sr + 2h (C) Sy = h - Sr YEAR 2009

TWO MARK

Q. 46

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

Q. 47

A plate load test is carried out on a 300 mm # 300 mm plate placed at 2 m below the ground level to determine the bearing capacity of a 2 m # 2 m footing placed at same depth of 2 m on a homogeneous sand deposit extending 10 m below ground. The ground water table is 3 m below the ground level. Which of the following factors does not require a correction to the bearing capacity determined based on the load test ? (A) Absence of the overburden pressure during the test (B) Size of the plate is much smaller than the footing size (C) Influence of the ground water table (D) Settlement is recorded only over a limited period of one or two days

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Common Data For Q. 48 and 49 : Examine the test arrangement and the soil properties given below :

The maximum pressure that can be applied with a factor of safety of 3 through the concrete block, ensuring no bearing capacity failure in soil using Terzaghi’s bearing capacity equation without considering the shape factor, depth factor and inclination factor is (A) 26.67 kPa (B) 60 kPa

Q. 48

(C) 90 kPa (D) 120 kPa

The maximum resistance offered by the soil through skin friction while pulling out the pile from the ground is (A) 104.9 kN (B) 209.8 kN (C) 236 kN (D) 472 kN

Q. 49

Statement for Linked Q. 50 and 51 : Q. 50

A saturated undisturbed sample from a clay strata has moisture content to 22.22% and specific weight of 2.7. Assuming gw = 10 kN/m3 , the void ratio and the saturated unit weight of the clay, respectively are (A) 0.6 and 16.875 kN/m3 (B) 0.3 and 20.625 kN/m3 (C) 0.6 and 20.625 kN/m3 (D) 0.3 and 16.975 kN/m3

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Q. 51


Using the properties of the clay layer derived from the above question, the consolidation settlement of the same clay layer under a square footing (neglecting its self weight) with additional data shown in the figure below (assume the stress distribution as 1 H : 2 V from the edge of the footing and gw = 10 kN/m3 ) is

(A) 32.78 mm (C) 79.5 mm YEAR 2008

(B) 61.75 mm (D) 131.13 mm ONE MARK

Q. 52

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

Q. 53

When a retaining wall moves away from the backfill, the pressure exerted on the wall is termed as (A) passive earth pressure (B) swelling pressure (C) pore pressure (D) active earth pressure

Q. 54

Compaction by vibratory roller is the best method of compaction i case of (A) moist silty sand (B) well graded dry sand (C) clay of medium compressibility (D) silt of high compressibility YEAR 2008

TWO MARKS

Q. 55

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

Q. 56

A footing 2 m # 1 m exerts a uniform pressure of 150 kN/m2 on the soil. Assuming a load dispersion of 2 vertical to 1 horizontal, the average vertical stress (kN/m2) at 1.0 m below the footing is (A) 50 (B) 75 (C) 80 (D) 100

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Q. 57

A direct shear test was conducted on a cohesion less soil (C = 0) specimen under a normal stress of 200 kN/m2 . The specimen failed at a shear stress of 100 kN/m2 . The angle of internal friction of the soil (degree) is (A) 26.6 (B) 29.5 (C) 30.0 (D) 32.6

Q. 58

A pile of 0.50 m diameter and of length 10 m is embedded in a deposit of clay. The undrained strength parameters of the clay are cohesion = 60 kN/m2 and the angle of internal friction = 0 . The skin friction capacity (kN) of the pile for an adhesion factor of 0.6, is (A) 671 (B) 565 (C) 283

(D) 106

Q. 59

A saturated clay stratum draining both at the top and bottom undergoes 50 per cent consolidation in 16 year under an applied load. If an additional drainage layer were present at the middle of the clay stratum, 50 per cent consolidation would occur in (A) 2 years (B) 4 years (C) 8 years (D) 16 years

Q. 60

A test plate 30 m # 30 m cm resting on a sand deposit settles by 10 mm under a certain intensity. A footing 150 cm # 200 cm resting on the same sand deposit and loaded to the same load intensity settles by (A) 2.0 mm (B) 27.8 mm (C) 30.2 mm (D) 50.0 mm

Q. 61

A volume of 3.0 # 106 m3 of groundwater was pumped form an unconfined aquifer uniformly from an area of 5 km2 . The pumping lowered the water table form initial level of 102 m to 99 m. The specific yield of the aquifer is (A) 0.20 (B) 0.30 (C) 0.40

(D) 0.50

Statement for Linked Q. 62 and 63 : The ground conditions at a site are shown in the figure below.

Q. 62

The saturated unit weight of the sand (kN/m3) is (B) 18 (A) 15 (C) 21 (D) 24

Q. 63

The total stress, pore water pressure and effective stress (kN/m2) at the point P are, respectively (A) 75, 50 and 25 (B) 90, 50 and 40 (C) 105, 50 and 55 (D) 120, 50 and 70

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Statement for Linked Q. 64 and 65 : A column is supported on a footing as shown in the figure below. The water table is at a depth of 10 m below the base of the footing.

Q. 64

The net ultimate bearing capacity (kN/m2) of the footing based on Terzaghi’s bearing capacity equation is (A) 216 (B) 432 (C) 630

Q. 65

(D) 846

The safe load (kN) that the footing can carry with a factor of safety 3 is (A) 282 (B) 648 (C) 945 (D) 1269 ONE MARK

YEAR 2007 Q. 66

A clay soil sample is tested in a triaxial apparatus in consolidated-drained conditions at a cell pressure of 100 kN/m2 . What will be the pore water pressure at a deviator stress of 40 kN/m2 ? (A) 0 (B) 20 kN/m2 (C) 40 kN/m2

Q. 67

The number of blows observed in a Standard Penetration Test (SPT) for different penetration depths are given as follows : Penetration of sampler Number of blows 0 - 150 mm 6 150 - 300 mm 8 300 - 450 mm 10 The observed N value is (A) 8 (C) 18

Q. 68

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(D) 60 kN/m2

(B) 14 (D) 24

The vertical stress at some depth below the corner of a 2 m # 3 m rectangular footing due to a certain load intensity is 100 kN/m2 . What will be the vertical stress in kN/m2 below the centre of a 4 m # 6 m rectangular footing at the same depth and same load intensity ? (A) 25 (B) 100 (C) 200 (D) 400



YEAR 2007

TWO MARKS

Q. 69

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 m sieves are 40% and 18%, respectively. The soil may be classified as (A) SC (B) MI (C) CI (D) SM

Q. 70

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

Q. 71

(D) 18.5, 0.45

The factor of safety of an infinite soil slope shown in the figure having the properties C = 0 , f = 35c, gdry = 16 kN/m3 and gsat = 20 kN/m3 is approximately equal to

(B) 0.80 (D) 1.20

(A) 0.70 (C) 1.00 Q. 72

Match List I with List II and select the correct answer using the codes given below the lists : List I List II a. Constant head permeability test 1. Pile foundation b. Consolidation test 2. Specific gravity c. Pycnometer test 3. Clay soil d. Negative skin friction 4. Sand

Codes : a (A) 4 (B) 4 (C) 3 (D) 4

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b 3 2 4 1

c 2 3 2 2

d 1 1 1 3



The bearing capacity of a rectangular footing of plan dimensions 1.5 m # 3 m resting on the surface of a sand deposit was estimated as 600 kN/m2 when the water table is far below the base of the footing. The bearing capacities in kN/m2 when the water level rises to depths of 3 m, 1.5 m and 0.5 below the base of the footing are (A) 600, 600, 400 (B) 600, 450, 350

Q. 73

(C) 600, 500, 250

(D) 600, 400, 250

What is the ultimate capacity in kN of the pile group shown in the figure assuming the group to fail as a single block ?

Q. 74

(A) 921.6 (C) 2438.6

(B) 1177.6 (D) 2481.6

Common Data For Q. 75 and 76 : Water is flowing through the permeability apparatus shown in the figure. The coefficient of permeability of the soil is 'k' m/s and the porosity of the soil sample is 0.50.

Q. 75

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The total head, elevation head and pressure head in metres of water at the point R shown in the figure are (A) 0.8, 0.4, 0.4 (B) 1.2, 0.4, 0.8 (C) 0.4, 0, 0.4 (D) 1.6, 0.4, 1.2



What are the discharge velocity and seepage velocity through the soil sample ? (A) k, 2k (B) 2 k, 4 k 3 3 (C) 2k, k (D) 4 k, 2 k 3 3

Q. 76

Statement for Linked Q. 77 and 78 : The ground conditions at a site are as shown in the figure. The water table at the site which was initially at a depth of 5 m below the ground level got permanently lowered to a depth of 15 m below the ground level due to pumping of water over a few years. Assume the following data : I unit weight of water = 10 kN/m3 II unit weight of sand above water table = 18 kN/m3 III unit weight of sand and clay below the water table = 20 kN/m3 IV coefficient of volume compressibility = 0.25 m2 MN

Q. 77

What is the change in the effective stress in kN/m2 at mid-depth of the clay layer due to the lowering of the water table ? (A) 0 (B) 20 (C) 80 (D) 100

Q. 78

What is the compression of the clay layer in mm due to the lowering of the water table ? (A) 125 (B) 100 (C) 25 (D) 0 YEAR 2006

Q. 79

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ONE MARK

Which of the following statement in Not in the context of capillary pressure in solids ? (A) Water is under tension in capillary zone (B) Pore water pressure is negative in capillary zone (C) Effective stress increases due to the capillary zone (D) Capillary pressure is more in coarse grained soils


Q. 80

For steady flow to a fully penetrating well in a confined aquifer, the draw downs at radial distances of r1 and r2 from the well have been measured as s1 and s2 respectively, for a pumping rate of Q . The transmissivity of the aquifer is equal to r2 Q f ln r1 p Q ln (r2 - r1) (A) (B) 2p (s1 - s2) 2p s1 - s2 (C)

Q. 81


r /r Q ln 2 1 2p =s2 /s1G

(D) 2pQ r2 - r1 ln a s2 k s1

The range of void ratio between which quick sand condition occurs in cohesionless granular soil deposits is (A) 0.4 - 0.5 (B) 0.6 - 0.7 (C) 0.8 - 0.9

(D) 1.0 - 1.1

Q. 82

To provide safety against piping failure, with a factor of safety of 5, what should be the maximum permissible exit gradient for soil with specific gravity of 2.5 and porosity of 0.35 ? (A) 0.155 (B) 0.167 (C) 0.195 (D) 0.213

Q. 83

Figure given below shows a smooth vertical gravity retaining wall with cohesionless soil backfill having an angle of internal friction f. In the graphical representation of Rankine’s active earth pressure for the retaining wall shown in figure, length OP represents

(A) vertical stress at the base (B) vertical stress at a height H/3 from the base (C) lateral earth pressure at the base (D) lateral earth pressure at a height H/3 from the base YEAR 2006 Q. 84

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TWO MARKS

A sample of saturated cohensionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30c. The deviatoric stress at failure for the sample at a confining pressure of 200 kPa is equal to (A) 200 kPa (B) 400 kPa (C) 600 kPa (D) 800 kPa



List I below gives the possible types of failure for a finite soil slope and List II gives the reasons for these different types of failure. Match the items in List I with the items in List II and select the correct answer from the codes given below the lists : List I List II a. Base failure 1. Soils above and below the toe have same strength b. Face failure 2. Soil above and toe is comparatively weaker c. Toe failure 3. Soil above the toe is comparatively stronger

Q. 85

Codes : a (A) 1 (B) 2 (C) 2 (D) 3

b 2 3 1 2

c 3 1 3 1

For the soil profile shown in Figure below, the minimum number of precast concrete piles of 300 mm diameter required of safely carry the load for a given factor of safety of 2.5 (assuming 100% efficiency for the pile group) is equal to

Q. 86

(A) 10 (C) 20

(B) 15 (D) 25

In a standard proctor test, 1.8 kg of moist soil was filling the mould (volume = 94.4 cc) after compaction. A soil sample weighing 23 g was taken from the mould and ovendried for 24 hours at a temperature of 110cC . Weight of the dry sample was found to be 20 g. Specific gravity of soil solids is G = 2.7 . The theoretical maximum value of the dry unit weight of the soil at the water content is equal to (B) 11.5 kN/m3 (A) 4.67 kN/m3 (C) 16.26 kN/m3 (D) 18.85 kN/m3

Q. 87

Statement for Linked Q. 88 and 89 : The average effective overburden pressure on 10 m thick homogeneous saturated clay layer is 150 kPa. Consolidation test on an undisturbed soil sample taken from the clay layer showed that the void ratio decreased from 0.6 to 0.5 by increased the stress intensity from 100 kPa to 300 kPa (G = 2.65).

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Q. 88

The initial void ratio of the clay layer is (A) 0.209 (B) 0.563 (C) 0.746 (D) 1.000

Q. 89

The total consolidation settlement of the clay layer due to the construction of a structure imposing an additional stress intensity of 200 kPa is (A) 0.10 m (B) 0.25 m (C) 0.35 m

(D) 0.50 m

Statement for Linked Q. 90 and 91 : Laboratory sieve analysis was carried out on a soil sample using a complete set of standard IS sieves. Out of 500 g of soil used in the test, 200 g was retained on IS 600 m sieve, 250 g was retained on IS 500 m sieve and the remaining 50 g was retained on IS 425 m sieve. Q. 90

The coefficient of uniformly of the soil is (A) 0.9 (B) 1.0 (C) 1.1 (D) 1.2

Q. 91

The classification of the soil is (A) SP (C) GP

(B) SW (D) GW

YEAR 2005

ONE MARK

Q. 92

Root time method is used to determine (A) T , time factor (B) Cv , coefficient of consolidation (C) av , coefficient of compressibility (D) mv , coefficient of volume compressibility

Q. 93

Negative skin friction in a soil is considered when the pile is constructed through a (A) fill material (B) dense coarse sand (C) over consolidated stiff clay (D) dense fine sand

Q. 94

There are two footings resting on the grounds surface. One footing is square of dimension 'B' . The other is strip footing of width 'B' . Both of them are subjected to a loading intensity of q . The pressure intensity at any depth below the base of the footing along the centre line would be (A) equal in both footings (B) large for square footing and small for strip footing (C) large for strip footing and small for square footing (D) more for strip footing at shallow depth (# B) and more for square footing at large depth (> B)

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Q. 95


A clayey soil has a maximum dry density of 16 kN/m3 and optimum moisture content of 12%. A contractor during the construction of core of an earth dam obtained the dry density 15.2 kN/m3 and water content 11%. This construction is acceptable because (A) the density is less than the maximum dry density and water content is on dry side of optimum (B) the compaction density is very low and water content is less than 12% (C) the compaction is done on the dry side of the optimum (D) both the dry density and water content of the compacted soil are within the desirable limits TWO MARKS

YEAR 2005 Q. 96

2

In a constant head parameter with cross section area of 10 cm , when the flow was taking place under a hydraulic gradient of 0.5, the amount of water collected in 60 seconds is 600 cc. The permeability of the soil is (A) 0.002 cm/s (B) 0.02 cm/s (C) 0.2 cm/s

Q. 97

Two observation wells penetrated into a confined aquifer and located 1.5 km apart in the direction of flow, indicate head of 45 m and 20 m. If the coefficient of permeability of the aquifer is 30 m/day and porosity is 0.25, the time of travel of an inert tracer from one well to another is (A) 416.7 days (B) 500 days (C) 750 days

Q. 98

(D) 2.0 cm/s

(D) 3000 days

Assuming that a river bed level does not change and the depth of water in river was 10 m, 15 m and 8 m during the months of February, July and December respectively of a particular year. The average bulk density of the soil is 20 kN/m3 . The density of water is 10 kN/m3 . The effective stress at a depth of 10 m below the river bed during these months would be (A) 300 kN/m2 in February, 350 kN/m2 July and 320 kN/m2 in December (B) 100 kN/m2 in February, 100 kN/m2 July and 100 kN/m2 in December (C) 200 kN/m2 in February, 250 kN/m2 July and 180 kN/m2 in December (D) 300 kN/m2 in February, 250 kN/m2 July and 280 kN/m2 in December

Q. 99

For a triaxial shear test conducted on a sand specimen at a confining pressure of 100 kN/m2 under drained conditions, resulted in a deviator stress (s1 - s3) at failure of 100 kN/m2 . The angle of shearing resistance of the soil would be (A) 18.43c (B) 19.47c (C) 26.56c (D) 30c

Q. 100

A 3 m high retaining wall is supporting a saturated sand (saturated due to capillary action) of bulk density 18 kN/m3 and angle of shearing resistance 30c . The change in magnitude of active earth pressure at the base due to rise in ground water table from the base of the footing to the ground surface shall (gw = 10 kN/m3) (A) increase by 20 kN/m2 (B) decrease by 20 kN/m2 (C) increase by 30 kN/m2 (D) decrease by 30 kN/m2

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Q. 101


For two infinite slopes (one in dry condition and other in submerged condition) in a sand deposit having the angle of shearing resistance 30c, factor of safety was determined as 1.5 (for both slopes). The slope angles would have been (A) 21.05c for dry slope and 21.05c for submerged slope (B) 19.47c for dry slope and 18.40c for submerged slope (C) 18.4c for dry slope and 21.05c for submerged slope (D) 22.6c for dry slope and 19.47c for submerged slope

Q. 102

A strip footing (8 m wide) is designed for a total settlement of 40 mm. The safe bearing capacity (shear) was 150 kN/m2 and safe allowable soil pressure was 100 kN/m2 . Due to important of the structure, now the footing is to be redesigned for total settlement of 25 mm. The new width of the footing will be (A) 5 m (B) 8 m (C) 12 m

Q. 103

(D) 12.8 m

During the subsurface investigations for design of foundations, a standard penetration test was conducted at 4.5 m below the ground surface. The record of number of blow is given below : Penetration depth (cm) Number of blows 0 - 7.5 3 7.5 - 15 3 15 - 22.5 6 22.5 - 30 6 30 - 37.5 8 37.5 - 45 7

Assuming the water table at ground level, soil as fine sand and correction factor for overburden as 1.0, the corrected 'N value for the soil would be (A) 18 (B) 19 (C) 21 (D) 33 Q. 104

A soil mass contains 40% gravel, 50 % sand and 10% silt. This soil can be classified as (A) silty sandy gravel having coefficient of uniformly less than 60. (B) silty gravelly sand having coefficient of uniformly equal to 10. (C) gravelly silty sand having coefficient of uniformly greater than 60. (D) gravelly silty sand and its coefficient of uniformity cannot be determined.

Q. 105

A saturated soil mass has a total density 22 kN/m3 and a water content of 10%. The bulk density and dry density of this soil are (A) 12 kN/m3 and 20 kN/m3 respectively (B) 22 kN/m3 and 20 kN/m3 respectively (C) 19.8 kN/m3 and 19.8 kN/m3 respectively (D) 23.2 kN/m3 and 19.8 kN/m3 respectively

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YEAR 2004 Q. 106

ONE MARK

A 10 m thick clay layer is underlain by a sand layer of 20 m depth (see figure below). The water table is 5 m below the surface of clay layer. The soil above the water table is capillary saturated. The value of gsat is 19 kN/m3 . The unit weight of water is gw . If now the water table rises to the surface, the effective stress at at point P on the interface will

(A) increase by 5gw (B) remain unchanged (C) decrease by 5gw (D) decrease by 10gw Q. 107

A unit volume of a mass of saturated soil is subjected to horizontal seepage. The saturated unit weight is 22 kN/m3 and the hydraulic gradient is 0.3. The resultant body force on the soil mass is (A) 1.98 kN (B) 6.6 kN (C) 11.49 kN

(D) 22.97 kN

Q. 108

In an undrained triaxial test on a saturated clay, the Poisson’s ratio is (A) s3 (B) s3 s1 + s3 s1 - s3 s s 3 (C) 1 (D) s1 + s3 s3 s3

Q. 109

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 (B) 10 kN/m2 (A) 5 kN/m2 (C) 20 kN/m2 (D) 200 kN/m2

Q. 110

Two circular footings of diameters D1 and D2 are resting on the surface of the same purely cohesive soil. The ratio of their gross ultimate bearing capacities is (A) D1 (B) 1.0 D2 2 (D) D2 (C) b D1 l D1 D2

Q. 111

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

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YEAR 2004 Q. 112

TWO MARKS

The figure given below represents the contact pressure distribution under beneath a

(A) rigid footing on saturated clay (B) rigid footing on sand (C) flexible footing on saturated clay (D) flexible footing on sand Q. 113

A 6 m thick clay layer undergoes 90% consolidation four times faster under twoway drainage as compared to one-way drainage. In an identical clay layer of 15 m thickness, two-way drainage will be faster as compared to one-way drainage by (A) 8 times (B) 4 times (C) 2.5 times (D) 2 times

Q. 114

The figure below shows two flow lines for seepage across an interface between two soil media or different coefficients of permeability. If entrance angle a1 = 30c, the exit angle a2 will be

(A) 7.50c (C) 66.59c

(B) 14.03c (D) 75.96c

Q. 115

An unsupported excavation is made to the maximum possible depth in a clay soil having gt = 18 kN/m3 , c = 100 kN/m2, f = 30c. The active earth pressure, according to Rankine’s theory, at the base level of the excavation is (A) 115.47 kN/m2 (B) 54.36 kN/m2 (C) 27.18 kN/m2 (D) 13.0 kN/m2

Q. 116

A retaining wall of height 8 m retains dry sand. In the initial state, the soil is loose and has a void ratio of 0.5, gd = 35c kN/m3 and f = 30c. Subsequently, the backfill is compacted to a state where void ratio is 0.4, gd = 18.8 kN/m3 and f = 35c. The ratio of initial passive thrust to the final passive thrust, according to Rankine’s earth pressure theory, is (A) 0.38 (B) 0.64 (C) 0.77 (D) 1.55

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Q. 117

An infinite soil slope with an inclination of 35c is subjected to seepage parallel to its surface. The soil has C l = 100 kN/m2 and f = 35c. Using the concept of mobilized cohesion and friction, at a factor of safety of 1.5 with respect of shear strength, the mobilized friction angle is (A) 20.02c (B) 21.05c (C) 23.33c (D) 30.00c

Q. 118

Using fu = 0 analysis and assuming planar failure as shown, the minimum factor of safety against shear failure of a vertical of height 4 m in a pure clay having cu = 120 kN/m2 and gsat = 20 kN/m3 is

Q. 119

(A) 1

(B) 6

(C) 10

(D) 20

In the context of collecting undisturbed soil samples of high quality using a spoon sampler, following statements are made : 1. Area ratio should be less than 10% 2. Clearance ratio should be less than 1% With reference to above statements, which of the following applies ? (A) Both the statements are true (B) Statements 2 is true but 1 is false (C) Statement 1 is true but 2 is false (D) Both the statements are false

Common Data For Q. 120 and 121 : A group of 16 piles of 10 m length and 0.5 m diameter is installed in a 10 m thick stiff clay layer underlain by rock. The pile-soil adhesion factor is 0.4; average shear strength of soil on the sides is 100 kPa; undrained shear strength of the soil at the base is also 100 kPa. Q. 120

The base resistance of a single pile is (A) 40.00 kN (B) 88.35 kN (C) 100.00 kN (D) 176.71 kN

Q. 121

Assuming 100% efficiency, the group side resistance is (A) 5026.5 kN (B) 10000.0 kN (C) 10053.1 kN (D) 20106.0 kN

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YEAR 2003 Q. 122

ONE MARK

A masonry dam is founded on previous sand having porosity equal to 45% and specific gravity of sand particles is 2.65. For a desired factor of safety of 3 against sand boiling, the maximum permissible upward gradient will be (A) 0.225 (B) 0.302 (C) 1.0 (D) None of these

Q. 123

Water is pumped from a well tapping an unconfined aquifer at a certain discharge rate and the steady state draw down (X) in an observation well is monitored. Subsequently, the pumping discharge is doubled and the steady state draw down in the same observation well is found to be more than double (i.e., more than 2X). This disproportionate draw down is caused by (A) well losses (B) decrease in the saturated thickness of the aquifer (C) nonlinear flow (D) delayed gravity yield

Q. 124

A double draining clay layer, 6 m thick, settles by 30 mm in three years under influence of certain loads. Its final consolidation settlement has been estimated to be 120 mm. If a thin layer of sand having negligible thickness is introduced at a depth of 1.5 m below the top surface, the final consolidation settlement of clay layer will be (A) 60 mm (B) 120 mm (C) 240 mm (D) None of these

Q. 125

A 25 kN point load acts on the surface of an infinite elastic medium. The vertical pressure intensity in kN/m2 at a point 6.0 m below and 4.0 m away from the load will be (A) 132 (B) 13.2 (C) 1.32 (D) 0.132

Q. 126

A granular soil possesses saturated density of 20 kN/m3 . Its effective angle of internal friction is 35 degrees. If the desired factor of safety is 1.5, the safe angle of slope for this soil, when seepage occurs at and parallel to the slope surface, will be (A) 25c (B) 23c (C) 20c (D) 13c

Q. 127

In a plate test conducted on cohesion less soil, a 600 mm square test plate settles by 15 mm under a load intensity of 0.2 N/mm2 . All conditions remaining the same, settlement of a 1 m square footing will be (A) less than 15 mm (B) greater than 25 mm (C) 15.60 mm (D) 20.50 mm

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YEAR 2003 Q. 128

For the soil strata shown in figure, the water tables is lowered by drainage by 2 m and if the top 2 m thick silty sand stratum remains saturated by capillary action even after lowering of water table, the increase in effective vertical pressure in kPa at mid-height of clay layer will be

(A) 0.2 (C) 20 Q. 129

TWO MARKS

(B) 2 (D) 200

At a reclamation site for which the soil strata is shown in fig. a 3 m thick layer of a fill material is to be laid instantaneously on the top surface. If the coefficient of volume compressibility, mv for clay is 2.2 # 10- 4 m2 /kN , the consolidation settlement of the clay layer due to placing of fill material will be

(A) 69.5 mm (B) 139 mm (C) 228 mm (D) 278 mm Q. 130

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A braced cut 5 m wide and 7.5 m deep is proposed in a cohesionless soil deposit having effective cohesion C l = 0 and effective friction angle, fl = 36c. The first row of struts is to be installed at a depth of 0.5 m below ground surface and spacing between the struts should be 1.5 m. If the horizontal spacing of struts is 3 m and unit weight of the deposit is 20 kN/m2 , the maximum strut load will be (A) 70.87 kN (B) 98.72 kN (C) 113.90 kN (D) 151.86 kN


Q. 131


For the (3 # 3) pile group shown in the figure, the settlement of pile group, in a normally consolidated clay stratum having properties as shown in the figure, will be

(A) 13.2 mm (C) 7.345 mm

(B) 12.775 mm (D) None of these

Q. 132

Compaction of an embankment is carried out in 500 mm thick layers. The rammer used for compaction has a foot area of 0.05 m2 and the energy imparted in every drop of rammer is 400 Nm. Assuming 50% more energy in each pass over the compacted area due to overlap, the number of passes required to develop compactive energy equivalent of Indian Standard light compaction for each layer would be (A) 10 (B) 16 (C) 20 (D) 26

Q. 133

Match the List I (Boring methods) with List II (Field conditions) and select the correct answer using the codes given below the lists : List I List II a. Auger Boring 1. Below water table in all soil types except hard soils and rocks b. Wash Boring 2. Large diameter bore holes over 150 mm in c. Percussion Drilling d. Rotary Drilling size 3. Exploration for shallow foundations and highways 4. Bouldery and gravelly strata

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Codes : a (A) 3 (B) 1 (C) 2 (D) 3 Q. 134

b 1 2 3 1


c 4 4 4 2

d 2 3 1 4

Match the items of List I with List II and select the correct answer using the codes given below the lists : List I List II a. Modulus of subgrade reaction 1. Cyclic pile load test b. Relative density and strength 2. Pressure meter test c. Skin friction and point bearing 3. Plate load test resistance 4. Standard penetration tests d. Elastic constants 5. Dynamic cone penetration test

Codes : (A) (B) (C) (D)

a 1 1 2 3

b 3 2 5 4

c 2 4 1 1

d 5 3 3 2

Common Data For Q. 135 and 136 : A canal having side slopes 1:1 is proposed to be constructed in a cohesive soil to a depth of 10 m below the ground surface. The soil properties are fu = 15c, Cu = 12 kPa, e = 1.0, Gs = 2.65 . Q. 135

If Taylor’s Stability Number, Sn is 0.08 and if the canal flows full, the factor of safety with respect to cohesion against failure of the canal bank slopes will be (A) 3.7 (B) 1.85 (C) 1.0 (D) None of these

Q. 136

If there is a sudden draw down of water in the canal and if Taylor’s Stability Number for the reduced value of fw is 0.126, the factor of safety with respect to cohesion against the failure of bank slopes will be (A) 1.85 (B) 1.18 (C) 0.84 (D) 0.53

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Common Data For Q. 137 and 138 : Figure shows the geometry of a strip footing supporting the load bearing walls of a three storied building and the properties of clay layer.

Q. 137

If the pressure acting on the footing is 40 kPa, the consolidation settlement of the footing will be (A) 0.89 mm (B) 8.9 mm (C) 89.0 mm (D) None of these

Q. 138

If the elastic modulus and the Poisson’s ratio of the clay layer are respectively 50 # 103 kPa and 0.4 and if the influence factor for the strip footing is 1.75, the elastic settlement of the footing will be (A) 0.41 mm (B) 1.41 mm (C) 14.1 mm (D) None of these YEAR 2002

ONE MARK

Q. 139

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 fond to be 45 and 33 percent respectively. The group symbol of the given soil as per IS : 1498 - 1970 is (A) SC (B) MI (C) CH (D) MH

Q. 140

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

Q. 141

The following data was obtained from a liquid test conducted on a soil sample Number of blows

17

Water content (%) 63.8 The liquid limit of the soil is (A) 63.1%% (C) 61.9%

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22

25

28

34

63.1

61.9

60.6

60.5

(B) 62.8% (D) 60.6%


Q. 142


When there is an increase in the atmospheric pressure, the water level in a well penetrating in a confined aquifer (A) increase (B) decreases (C) may inrease or decrease depending on the nature of the aquifer (D) does not undergo any change

Q. 143

The specific gravity and insitu void ratio of a soil deposit are 2.71 and 0.85 respectively. The value of the critical hydraulic gradient is (A) 0.82 (B) 0.85 (C) 0.92

Q. 144

(D) 0.92

The observed value of the standard penetration number (N ) at 10 m depth of silty sand deposit is 13. The unit weight of the soil is 16 kN/m3 . The N value after correcting for the presence of fines will be (A) 12 (B) 13 (C) 14 (D) 15 YEAR 2002

TWO MARKS

Q. 145

sThe time for a clay layer to achieve 85% consolidation is 10 years. If the layer was half as thick, 10 times more permeable and 4 times more compressible then the time that would be required to achieve the same degree of consolidation is (A) 1 year (B) 5 year (C) 12 years (D) 16 years

Q. 146

If the effective shear stress strength parameters of a soil are c' = 10 kPa and f' = 30c, the shear strength on a plane within the saturated soil mass at a point where the total normal stress is 300 kPa and pore water pressure is 150 kPa will be (A) 90.5 kPa (B) 96.6 kPa (C) 101.5 kPa (D) 105.5 kPa

Q. 147

In a tri-exial test carried out on a cohesionless soil sample with a cell pressure of 20 kPa, the observed value of applied stress at the point of failure was 40 kPa. The angle of internal friction of the soil is (A) 10º (B) 15º (C) 25º (D) 30º

Q. 148

An infinite slope is to be constructed in a soil. The effective stress strength parameters of the soil are c' = 0 and f' = 30c. The saturated unit weight of the slope is 20 kN/m3 and the unit weight of water is 10 kN/m3 . Assuming that seepage is occurring parallel to the slope, the maximum slope angle for a factor of safety of 1.5 would be (A) 10.89º (B) 11.30º (C) 12.48º (D) 14.73º

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YEAR 2001 Q. 149

ONE MARK

The following two statements are made with respect to different sand samples having the same relative density. Identify if they are true or false I. Poorly graded sands will have lower friction angle than the well graded sands. II. The particle size has no influence on the friction angle of sand. (A) II is true but I is false

(B) Both are false statements

(C) Both are true statements

(D) I is true but II is false

Q. 150

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

Q. 151

With respect to a c -f soil in an infinite slope, identify if the following two statements are True or False. I. The stable slope angle can be grater than f II. The factor of safety of the slope does not depend on the height of soil in the slope (A) Both statements are False (B) I is True but II is False (C) I is False but II is True

Q. 152

(D) Both statements are True

The following two statements are made with reference to the calculation of net bearing capacity of a footing in pure clay soil ^f = 0h using Terzaghi’s bearing capacity theory. Identify if they are True or False I. Increase in footing width will result in increase in bearing capacity. II. Increase in depth of foundation will result in higher bearing capacity (A) Both statements are True (B) Both statements are False (C) I is True but II is False (D) I is False but II is True

Q. 153

The width and depth of a footing are 2 and 1.5 m respectively. The water table at the site is at a depth of 3 m below the ground level. The water table correction factor for the calculation of the bearing capacity of soil is (A) 0.875 (B) 1.000 (C) 0.925 (D) 0.500 YEAR 2001

Q. 154

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TWO MARKS

The coefficients of permeability of a soil in horizontal and vertical directions are 3.46 and 1.5 m/day respectively. The base length of a concrete dam resting in this soil is 100 m . When the flow net is developed for this soil with 1 : 25 scale factor in the vertical direction, the reduced base length of the dam will be (A) 2.63 m (B) 4.00 m (C) 6.08 m (D) 5.43 m


Q. 155


Identify the two False statements from the following four statements I. The consolidation of soil happens due to the change in total stress. II. When Standard Penetration Tests are performed in fine sands below the water table, the dilation correction is applied after the overburden correction is applied. III. Over consolidated clays will have predominantly cohesive, strength as compared to the frictional strength. IV. Compaction of soils is due to expulsion of water. (A) II and III (C) I and III

Q. 156

(B) I and IV (D) II and IV

The critical slip circle for a slope is shown below along with the soil properties

The length of the arc of the slip circle is 15.6 m and the area of soil within the slip circle is 82 m2 . The radius of the slip circles is 10.3 m . The factor of safety against the slip circle failure is nearly equal to (A) 1.05 (B) 1.22 (C) 0.78 (D) 1.28 Q. 157

A plate load test was conducted in sand on a 300 mm diameter plate. If the plate settlement was 5 mm at a pressure of 100 kPa, the settlement (in mm) of a 5 m # 8 m rectangular footing at the same pressure will be (A) 9.4 (B) 18.6 (C) 12.7 (D) 17.8

Q. 158

Identify the two True statements from the following four statements. I. Negative skin friction is higher on floating piles than on end bearing piles II. All other things being the same is footings on sand, the footing with smaller width will have lower settlement at the same net pressure. III. The void ratio of soils in always less than 1.0 IV. For determining the depth of embedment of anchored sheet piles, net moment at the anchor elevation is set to zero. (A) I and IV (B) I and III (C) II and IV (D) II and III

**********

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ANSWER KEY GEOTECHNICAL ENGINEERING 1

2

3

4

5

6

7

8

9

10

(C)

(C)

(C)

(C)

(D)

3.8 m

(A)

(A)

(*)

(*)

11

12

13

14

15

16

17

18

19

30

(A)

(B)

(B)

(B)

(A)

(A)

(D)

(A)

(B)

(C)

21

22

23

24

25

26

27

28

29

30

(B)

(B)

(D)

(A)

(A)

(B)

(C)

(B)

(D)

(B)

31

32

33

34

35

36

37

38

39

40

(B)

(C)

(D)

(B)

(B)

(D)

(B)

(B)

(B)

(C)

41

42

43

44

45

46

47

48

49

50

(C)

(B)

(C)

(B)

(C)

(B)

(C)

(A)

(A)

(C)

51

52

53

54

55

56

57

58

59

60

(C)

(C)

(D)

(B)

(B)

(A)

(A)

(B)

(B)

(B)

61

62

63

64

65

66

67

68

69

70

(A)

(C)

(C)

(C)

(C)

(A)

(C)

(D)

(A)

(A)

71

72

73

74

75

76

77

78

79

80

(A)

(A)

(A)

(D)

(A)

(A)

(D)

(A)

(D)

(A)

81

82

83

84

85

86

87

88

89

90

(B)

(C)

(A)

(B)

(D)

(C)

(D)

(B)

(D)

(D)

91

92

93

94

95

96

97

98

99

100

(A)

(B)

(A)

(C)

(A)

(D)

(C)

(B)

(B)

(A)

101

102

103

104

105

106

107

108

109

110

(A)

(A)

(C)

(D)

(B)

(C)

(D)

(A)

(C)

(B)

111

112

113

114

115

116

117

118

119

120

(B)

(A)

(B)

(C)

(A)

(C)

(B)

(B)

(C)

(D)

121

122

123

124

125

126

127

128

129

130

(C)

(B)

(C)

(B)

(D)

(D)

(D)

(C)

(B)

(C)

131

132

133

134

135

136

137

138

139

140

(D)

(D)

(A)

(B)

(B)

(D)

(C)

(B)

(C)

(C)

141

142

143

144

145

146

147

148

149

150

(C)

(D)

(C)

(B)

(A)

(B)

(D)

(A)

(D)

(C)

151

152

153

154

155

156

157

158

(B)

(B)

(A)

(A)

(B)

(D)

(D)

(C)

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