2022 101503

End Semester Examination - 2022

Time 03 Hours
Full Marks 70
Instructions:
  • The marks are indicated in the right-hand margin.
  • There are NINE questions in this paper.
  • Attempt FIVE questions in all.
  • Question No. 1 is compulsory.

Q.1 Choose the correct answer of the following (Any seven question only):

Q1.1

Lacustrine soil is a

a)

soil deposited in sea

b)

wind borne soil

c)

soil deposited in lake

d)

None of the above

Q1.2

The hydraulic head that would produce a quick sand condition in a sand stratum of thickness 1.5 m having specific gravity as 2.67 and voids ratio as 0.67 is equal to.

a)

1 m

b)

1.5 m

c)

2.0 m

d)

3.0 m

Q1.3

Which of the following statement are true about quick sand condition?

a)

It is only a condition but not a type of sand.

b)

It is condition and type of sand too.

c)

Quick sand condition occurs more commonly in fine grained.

d)

Quick sand condition reaches when critical hydraulic gradient is less than unity.

Q1.4

The void ratio of a soil mass can

a)

Never be greater than 1

b)

Be zero

c)

Any value greater than zero

d)

0 to 1

Q1.5

In hydrometer analysis for a soil mass

a)

Both meniscus correction and dispersing agent correction are negative.

b)

Both meniscus correction and dispersing agent correction are positive.

c)

Meniscus correction is positive while dispersing agent correction is negative.

d)

Meniscus correction is negative while dispersing agent correction is positive.

Q1.6

The Westergaard's analysis is used for

a)

Homogeneous soils

b)

Cohesive soils

c)

Sandy soil

d)

Stratified soils

Q1.7

Group symbols assigned to silty sand and clayey sand are respectively

a)

SS & CS

b)

SM & CS

c)

SM & SC

d)

MS & CS

Q1.8

Toughness Index of a soil is the ratio of

a)

Plasticity index to the flow index

b)

Liquidity index to the flow index

c)

Consistency index to the flow index

d)

Shrinkage index to the flow index

Q1.9

An isobar is a curve which

a)

Joins points of equal horizontal stress

b)

Joins points of equal vertical stress

c)

Joins points of zero vertical stress

d)

Joins points of maximum vertical stress

Q1.10

The water of a highly organic soil is determined in an over a temperature of:

a)

105°C

b)

80°C

c)

60°C

d)

27°C

Q.2 Solve both questions :

Q2.1

What do you understand by contact pressure? Draw the contact pressure distribution diagram for flexible and rigid footing on sand and clay.

Q2.2

Calculate the vertical stress at a point P at a depth of 2.5 m directly under the centre of the circular area of radius 2 m and subjected to a load of 100 kN/m². Also calculate the vertical stress at a point Q which is at the same depth of 2.5 m and 2.5 m away from the centre of the loaded area.

Q.3 Solve both questions :

Q3.1

Define Thixotropy, sensitivity and activity number

Q3.2

A well penetrates into an unconfined aquifer having a saturated depth of 100 m. The discharge is 250 lit/min at 12 m drawdown. Assuming equilibrium flow conditions and homogenous aquifer, estimate the discharge at 18 m drawdown.

Q.4 Solve both questions :

Q4.1

A horizontal stratified deposit consists of four layers each uniform in itself. The permeability of the layers are $ 7.5 \times 10^{-4} \text{ cm/sec} $, $ 49 \times 10^{-4} \text{ cm/sec} $, $ 13 \times 10^{-1} \text{ cm/sec} $ and $ 17 \times 10^{-4} \text{ cm/sec} $ and their thickness are 5 m, 4 m, 17 m and 6 m respectively. Find the effective average permeability of the deposit in horizontal and vertical directions.

Q4.2

A fill having a volume 10,00,000 cubic meters is to be constructed at a void ratio of 0.73. The soil is required to be excavated from a pit having a void ratio of 1.2. Estimate the volume of excavated soil from the borrow pit in cubic meters and also find the number of trips required by a truck if its load-carrying capacity is 20,000 cubic meters.

Q.5 Solve both questions :

Q5.1

A natural soil deposit has a bulk unit weight of 18.44 kN/m³ and water content of 5%. Calculate the amount of water required to be added to 1 cubic metre of soil to raise the water content to 15%. Assume the void ratio to remain constant. What will be the degree of saturation. Assume G=2.67.

Q5.2

Briefly describe the factors affecting compaction?

Q.6 Solve both questions :

Q6.1

Explain Newmark's influence chart preparation and usage.

Q6.2

From the flow net diagram drawn for seepage flow through an earthen dam, the following data is obtained: Number of flow lines = 3.5; Number equi-potential drops = 10, Coefficient of permeability = $ 1.25 \times 10^{-5} \text{ cm/sec} $ and head causing seepage flow, h = 12.5 m. Compute the seepage through the body of the dam per unit length.

Q.7 Solve both questions :

Q7.1

A core cutter 12.6 cm in height and 10.2 cm in diameter weights 1071 gm when empty. It is used to determine the in-situ unit weight of an embankment. The weight of core cutter with soil is 2970 gm. (i) If the water content is 6%, what are the in-situ dry weight and porosity? (ii) If the embankment gets fully saturated due to heavy rains what will be the increase in water content and bulk unit weight, if no volume change occurs? The specific gravity of soils solids is 2.69.

Q7.2

The values of liquid limit, plastic limit and shrinkage limit of soil were reported as: $ W_L = 60\% $, $ W_P = 30\% $, $ W_S = 20\% $. If a sample of this soil at liquid limit has a volume of 40 cc and its volume measured at shrinkage limit was 23.5 cc, determine the specific gravity of the solids. What is the shrinkage ratio and volumetric shrinkage?

Q.8 Solve both questions :

Q8.1

Explain briefly the coarse grained and fine grained soil classification system as per Indian Standard.

Q8.2

A sample of clay was coated with paraffin wax and its mass, including the mass of wax, was found to be 697.5 gm. The sample was immersed in water and the volume of the water displaced was found to be 355 ml. The mass of the sample without wax was 690.0 gm and the water content of the representative specimen was 18%. Determine the bulk density, dry density, void ratio and the degree of saturation. The specific gravity of the solids was 2.70 and that of the wax was 0.89.

Q.9 Write short notes on any four of the following:

Q9.1
a)

Compaction by explosives

b)

Zero Air void line

c)

Effect of surcharge on effective stress

d)

Methods to increase the factor of safety against piping

e)

Importance of effective stress

f)

Darcy's law and its limitation.


2022 V2 101503

End Semester Examination - 2022

Time 03 Hours
Full Marks 70
Instructions:
  • The marks are indicated in the right-hand margin.
  • There are NINE questions in this paper.
  • Attempt FIVE questions in all.
  • Question No. 1 is compulsory.

Q.1 Choose the correct answer of the following (Any seven question only):

Q1.1

Lacustrine soil is a

a)

soil deposited in sea

b)

wind borne soil

c)

soil deposited in lake

d)

None of the above

Q1.2

The hydraulic head that would produce a quick sand condition in a sand stratum of thickness 1.5 m having specific gravity as 2.67 and voids ratio as 0.67 is equal to.

a)

1 m

b)

1.5 m

c)

2.0 m

d)

3.0 m

Q1.3

Which of the following statement are true about quick sand condition?

a)

It is only a condition but not a type of sand.

b)

It is condition and type of sand too.

c)

Quick sand condition occurs more commonly in fine grained.

d)

Quick sand condition reaches when critical hydraulic gradient is less than unity.

Q1.4

The void ratio of a soil mass can

a)

Never be greater than 1

b)

Be zero

c)

Any value greater than zero

d)

0 to 1

Q1.5

In hydrometer analysis for a soil mass

a)

Both meniscus correction and dispersing agent correction are negative.

b)

Both meniscus correction and dispersing agent correction are positive.

c)

Meniscus correction is positive while dispersing agent correction is negative.

d)

Meniscus correction is negative while dispersing agent correction is positive.

Q1.6

The Westergaard's analysis is used for

a)

Homogeneous soils

b)

Cohesive soils

c)

Sandy soil

d)

Stratified soils

Q1.7

Group symbols assigned to silty sand and clayey sand are respectively

a)

SS & CS

b)

SM & CS

c)

SM & SC

d)

MS & CS

Q1.8

Toughness Index of a soil is the ratio of

a)

Plasticity index to the flow index

b)

Liquidity index to the flow index

c)

Consistency index to the flow index

d)

Shrinkage index to the flow index

Q1.9

An isobar is a curve which

a)

Joins points of equal horizontal stress

b)

Joins points of equal vertical stress

c)

Joins points of zero vertical stress

d)

Joins points of maximum vertical stress

Q1.10

The water of a highly organic soil is determined in an over a temperature of:

a)

105°C

b)

80°C

c)

60°C

d)

27°C

Q.2 Solve both questions :

Q2.1

What do you understand by contact pressure? Draw the contact pressure distribution diagram for flexible and rigid footing on sand and clay.

Q2.2

Calculate the vertical stress at a point P at a depth of 2.5 m directly under the centre of the circular area of radius 2 m and subjected to a load of 100 kN/m². Also calculate the vertical stress at a point Q which is at the same depth of 2.5 m and 2.5 m away from the centre of the loaded area.

Q.3 Solve both questions :

Q3.1

Define Thixotropy, sensitivity and activity number

Q3.2

A well penetrates into an unconfined aquifer having a saturated depth of 100 m. The discharge is 250 lit/min at 12 m drawdown. Assuming equilibrium flow conditions and homogenous aquifer, estimate the discharge at 18 m drawdown.

Q.4 Solve both questions :

Q4.1

A horizontal stratified deposit consists of four layers each uniform in itself. The permeability of the layers are 7.5×104 cm/sec7.5 \times 10^{-4} \text{ cm/sec}, $ 49 \times 10^{-4} \text{ cm/sec} $, 13×101 cm/sec13 \times 10^{-1} \text{ cm/sec} and 17×104 cm/sec17 \times 10^{-4} \text{ cm/sec} and their thickness are 5 m, 4 m, 17 m and 6 m respectively. Find the effective average permeability of the deposit in horizontal and vertical directions.

Q4.2

A fill having a volume 10,00,000 cubic meters is to be constructed at a void ratio of 0.73. The soil is required to be excavated from a pit having a void ratio of 1.2. Estimate the volume of excavated soil from the borrow pit in cubic meters and also find the number of trips required by a truck if its load-carrying capacity is 20,000 cubic meters.

Q.5 Solve both questions :

Q5.1

A natural soil deposit has a bulk unit weight of 18.44 kN/m³ and water content of 5%. Calculate the amount of water required to be added to 1 cubic metre of soil to raise the water content to 15%. Assume the void ratio to remain constant. What will be the degree of saturation. Assume G=2.67.

Q5.2

Briefly describe the factors affecting compaction?

Q.6 Solve both questions :

Q6.1

Explain Newmark's influence chart preparation and usage.

Q6.2

From the flow net diagram drawn for seepage flow through an earthen dam, the following data is obtained: Number of flow lines = 3.5; Number equi-potential drops = 10, Coefficient of permeability = 1.25×105 cm/sec1.25 \times 10^{-5} \text{ cm/sec} and head causing seepage flow, h = 12.5 m. Compute the seepage through the body of the dam per unit length.

Q.7 Solve both questions :

Q7.1

A core cutter 12.6 cm in height and 10.2 cm in diameter weights 1071 gm when empty. It is used to determine the in-situ unit weight of an embankment. The weight of core cutter with soil is 2970 gm. (i) If the water content is 6%, what are the in-situ dry weight and porosity? (ii) If the embankment gets fully saturated due to heavy rains what will be the increase in water content and bulk unit weight, if no volume change occurs? The specific gravity of soils solids is 2.69.

Q7.2

The values of liquid limit, plastic limit and shrinkage limit of soil were reported as: $ W_L = 60% ,, W_P = 30% ,, W_S = 20% $. If a sample of this soil at liquid limit has a volume of 40 cc and its volume measured at shrinkage limit was 23.5 cc, determine the specific gravity of the solids. What is the shrinkage ratio and volumetric shrinkage?

Q.8 Solve both questions :

Q8.1

Explain briefly the coarse grained and fine grained soil classification system as per Indian Standard.

Q8.2

A sample of clay was coated with paraffin wax and its mass, including the mass of wax, was found to be 697.5 gm. The sample was immersed in water and the volume of the water displaced was found to be 355 ml. The mass of the sample without wax was 690.0 gm and the water content of the representative specimen was 18%. Determine the bulk density, dry density, void ratio and the degree of saturation. The specific gravity of the solids was 2.70 and that of the wax was 0.89.

Q.9 Write short notes on any four of the following:

Q9.1
  • Compaction by explosives
  • Zero Air void line
  • Effect of surcharge on effective stress
  • Methods to increase the factor of safety against piping
  • Importance of effective stress
  • Darcy's law and its limitation.
a)

Compaction by explosives

b)

Zero Air void line

c)

Effect of surcharge on effective stress

d)

Methods to increase the factor of safety against piping

e)

Importance of effective stress

f)

Darcy's law and its limitation.


2021 101503

B.Tech 5th Semester Examination, 2021

Time 03 Hours
Full Marks 70
Instructions:
  • The marks are indicated in the right-hand margin.
  • There are NINE questions in this paper.
  • Attempt FIVE questions in all.
  • Question No. 1 is compulsory.

Q.1 Choose the correct answer of the following (any seven):

Q1.1

Chemical weathering of rocks is characterized by: 1. change in chemical and mineralogical composition 2. disappearance of some minerals 3. formation of new secondary minerals. Correct answer is

a)

1 only

b)

1 and 2 only

c)

2 and 3 only

d)

1, 2 and 3

Q1.2

The bulk density of a soil mass below ground water table is equal to

a)

saturated density

b)

submerged density

c)

dry density

d)

relative density

Q1.3

The volume of a density bottle is usually

a)

25 ml

b)

50 ml

c)

900 ml

d)

1000 ml

Q1.4

Soil is in plastic state when the water content is between

a)

liquid limit and plastic limit

b)

plastic limit and shrinkage limit

c)

liquid limit and shrinkage limit

d)

shrinkage limit and zero

Q1.5

Wet sieve analysis is done for the soil passing

a)

75 µm

b)

4.75 µm

c)

10 mm

d)

20 mm

Q1.6

The maximum particle size for which Darcy's law is applicable is

a)

75 µm

b)

0.2 mm

c)

0.5 mm

d)

1.0 mm

Q1.7

A soil has a discharge velocity of $ 6 \times 10^{-6} \text{ m/s} $ and the porosity of 0.40. Its seepage velocity is

a)

0.150×106 m/s0.150 \times 10^{-6} \text{ m/s}

b)

1.5×106 m/s1.5 \times 10^{-6} \text{ m/s}

c)

2.4×106 m/s2.4 \times 10^{-6} \text{ m/s}

d)

6×106 m/s6 \times 10^{-6} \text{ m/s}

Q1.8

Quick sand is

a)

a type of sand

b)

a condition in which a cohesionless soil losses its strength because of upward flow of water

c)

a condition in which a cohesive soil losses its strength

d)

None of the above

Q1.9

The soil sample taken for IS light compaction test usually should pass through

a)

4.75 mm IS sieve

b)

10 mm IS sieve

c)

20 mm IS sieve

d)

40 mm IS sieve

Q1.10

A point load of 700 kN is applied on the surface of a thick layer of saturated clay. Using Boussinesq's equation, the estimated vertical stress at a depth of 2 m and a radial distance of 1.0 m from the point of application of the load is

a)

47.5 kPa

b)

47.7 kPa

c)

47.6 kPa

d)

47.8 kPa

Q.2 Solve both questions :

Q2.1

Explain the phenomena of formation and transportation of soils.

Q2.2

Explain the method of determination of liquid limit of soil by Casagrande's apparatus. What are the limitations of the method?

Q.3 Solve both questions :

Q3.1

From fundamental, derive an expression for dry density in terms of bulk unit weight and water content.

Q3.2

An earthen embankment under construction has a bulk unit weight of 17 kN/m³ and a moisture content of 12%. Compute the quantity of water in liters required to be added per cubic meter of earth to raise the moisture content to 16% at the same void ratio.

Q.4 Solve both questions :

Q4.1

Describe the Indian system of soil classification. When would you use dual symbols for soils?

Q4.2

Two soils $ S_1 $ and $ S_2 $ are tested in the laboratory for the consistency limits. The data available is as follows:

Soil S1 Soil S2
Plastic limit 21% 25%
Liquid limit 45% 65%
Flow index 8 10
Natural moisture content 40% 50%

(i) Which one is more plastic? (ii) Which one is better foundation material when remoulded? (iii) Which one has better strength as a function of water content? (iv) Which one has better strength at the plastic limit?

Q.5 Solve both questions :

Q5.1

What is flow net? Discuss the characteristics and uses of flow net.

Q5.2

The following data were recorded in a constant head permeability test: Internal diameter of permeameter = 7.5 cm, Head loss over a sample length of 18 cm = 24.7 cm, Quantity of water collected 100 sec = 1000 ml, Porosity of soil sample was 45%. Calculate the coefficient of permeability and discharge velocity.

Q.6 Solve both questions :

Q6.1

Explain the mechanism of piping in hydraulic structures. What methods are used to increase the factor of safety against piping?

Q6.2

A silt deposit consists of two layers. The top layer is 2.5 m thick (Unit weight = 18 kN/m³) and the bottom layer is 6.0 m thick (Unit weight = 19 kN/m³). The water table is at a depth of 4.0 m from the top. Draw the diagram showing the variation of total stress, neutral stress and effective stress.

Q.7 Solve both questions :

Q7.1

How the compaction improve the engineering properties of soil?

Q7.2

The following data is obtained in a compaction test: Bulk density (gm/cc): 1.97, 2.11, 2.42, 2.32, 2.30, 2.41. Moisture content (%): 8.81, 11.25, 14.05, 17.40, 19.25. Determine optimum moisture content and maximum dry density. Draw zero-air-void line. Assume $ G=2.68 $.

Q.8 Solve both questions :

Q8.1

Determine the vertical stress under a uniform circular load of intensity q and radius a using Westergaard's equation.

Q8.2

The wall of a building foundation of width 4 m and length 30 m carries a uniformly distributed load 300 kN/m². Compute the vertical stress along the centre of the foundation at a depth 4.0 m below the bottom of the foundation. Ignore the surcharge effect of the soil over the base level of the foundation.

Q.9 Write short notes on any four of the following:

Q9.1
a)

Black cotton soils

b)

Silt and clay

c)

Plasticity chart

d)

Piping

e)

Field compaction control

f)

Importance of pressure bulb


2021 V4 101503

B.Tech 5th Semester Examination, 2021

Time 03 Hours
Full Marks 70
Instructions:
  • The marks are indicated in the right-hand margin.
  • There are NINE questions in this paper.
  • Attempt FIVE questions in all.
  • Question No. 1 is compulsory.

Q.1 Choose the correct answer of the following (any seven):

Q1.1

Chemical weathering of rocks is characterized by: 1. change in chemical and mineralogical composition 2. disappearance of some minerals 3. formation of new secondary minerals. Correct answer is

a)

1 only

b)

1 and 2 only

c)

2 and 3 only

d)

1, 2 and 3

Q1.2

The bulk density of a soil mass below ground water table is equal to

a)

saturated density

b)

submerged density

c)

dry density

d)

relative density

Q1.3

The volume of a density bottle is usually

a)

25 ml

b)

50 ml

c)

900 ml

d)

1000 ml

Q1.4

Soil is in plastic state when the water content is between

a)

liquid limit and plastic limit

b)

plastic limit and shrinkage limit

c)

liquid limit and shrinkage limit

d)

shrinkage limit and zero

Q1.5

Wet sieve analysis is done for the soil passing

a)

75 µm

b)

4.75 µm

c)

10 mm

d)

20 mm

Q1.6

The maximum particle size for which Darcy's law is applicable is

a)

75 µm

b)

0.2 mm

c)

0.5 mm

d)

1.0 mm

Q1.7

A soil has a discharge velocity of $ 6 \times 10^{-6} \text{ m/s} $ and the porosity of 0.40. Its seepage velocity is

a)

0.150×106 m/s0.150 \times 10^{-6} \text{ m/s}

b)

1.5×106 m/s1.5 \times 10^{-6} \text{ m/s}

c)

2.4×106 m/s2.4 \times 10^{-6} \text{ m/s}

d)

6×106 m/s6 \times 10^{-6} \text{ m/s}

Q1.8

Quick sand is

a)

a type of sand

b)

a condition in which a cohesionless soil losses its strength because of upward flow of water

c)

a condition in which a cohesive soil losses its strength

d)

None of the above

Q1.9

The soil sample taken for IS light compaction test usually should pass through

a)

4.75 mm IS sieve

b)

10 mm IS sieve

c)

20 mm IS sieve

d)

40 mm IS sieve

Q1.10

A point load of 700 kN is applied on the surface of a thick layer of saturated clay. Using Boussinesq's equation, the estimated vertical stress at a depth of 2 m and a radial distance of 1.0 m from the point of application of the load is

a)

47.5 kPa

b)

47.7 kPa

c)

47.6 kPa

d)

47.8 kPa

Q.2 Solve both questions :

Q2.1

Explain the phenomena of formation and transportation of soils.

Q2.2

Explain the method of determination of liquid limit of soil by Casagrande's apparatus. What are the limitations of the method?

Q.3 Solve both questions :

Q3.1

From fundamental, derive an expression for dry density in terms of bulk unit weight and water content.

Q3.2

An earthen embankment under construction has a bulk unit weight of 17 kN/m³ and a moisture content of 12%. Compute the quantity of water in liters required to be added per cubic meter of earth to raise the moisture content to 16% at the same void ratio.

Q.4 Solve both questions :

Q4.1

Describe the Indian system of soil classification. When would you use dual symbols for soils?

Q4.2

Two soils $ S_1 $ and $ S_2 $ are tested in the laboratory for the consistency limits. The data available is as follows:

Soil S1 Soil S2
Plastic limit 21% 25%
Liquid limit 45% 65%
Flow index 8 10
Natural moisture content 40% 50%

(i) Which one is more plastic? (ii) Which one is better foundation material when remoulded? (iii) Which one has better strength as a function of water content? (iv) Which one has better strength at the plastic limit?

Q.5 Solve both questions :

Q5.1

What is flow net? Discuss the characteristics and uses of flow net.

Q5.2

The following data were recorded in a constant head permeability test: Internal diameter of permeameter = 7.5 cm, Head loss over a sample length of 18 cm = 24.7 cm, Quantity of water collected 100 sec = 1000 ml, Porosity of soil sample was 45%. Calculate the coefficient of permeability and discharge velocity.

Q.6 Solve both questions :

Q6.1

Explain the mechanism of piping in hydraulic structures. What methods are used to increase the factor of safety against piping?

Q6.2

A silt deposit consists of two layers. The top layer is 2.5 m thick (Unit weight = 18 kN/m³) and the bottom layer is 6.0 m thick (Unit weight = 19 kN/m³). The water table is at a depth of 4.0 m from the top. Draw the diagram showing the variation of total stress, neutral stress and effective stress.

Q.7 Solve both questions :

Q7.1

How the compaction improve the engineering properties of soil?

Q7.2

The following data is obtained in a compaction test: Bulk density (gm/cc): 1.97, 2.11, 2.42, 2.32, 2.30, 2.41. Moisture content (%): 8.81, 11.25, 14.05, 17.40, 19.25. Determine optimum moisture content and maximum dry density. Draw zero-air-void line. Assume $ G=2.68 $.

Q.8 Solve both questions :

Q8.1

Determine the vertical stress under a uniform circular load of intensity q and radius a using Westergaard's equation.

Q8.2

The wall of a building foundation of width 4 m and length 30 m carries a uniformly distributed load 300 kN/m². Compute the vertical stress along the centre of the foundation at a depth 4.0 m below the bottom of the foundation. Ignore the surcharge effect of the soil over the base level of the foundation.

Q.9 Write short notes on any four of the following:


2020 101503

B.Tech 5th Semester Exam., 2020

Time 3 hours
Full Marks 70
Instructions:
  • The marks are indicated in the right-hand margin.
  • There are NINE questions in this paper.
  • Attempt FIVE questions in all.
  • Question No. 1 is compulsory.

Q.1 Choose the correct answer of the following (any seven) :

Q1.1

Water transported soils are termed as

a)

alluvial

b)

aeoline

c)

talus

d)

loess

Q1.2

The three-phase soil system consists of

a)

soil, water and air

b)

soil, semi-solid and air

c)

solids, water and air

d)

solids, semi-solids and water

Q1.3

The standard and most accurate method for determination of water content is

a)

calcium carbide method

b)

torsion balance method

c)

oven drying method

d)

alcohol method

Q1.4

The property of fine grained soils to change from liquid state to plastic state with decrease of water content is known as

a)

liquidity

b)

plasticity

c)

shrinkage

d)

consistency

Q1.5

The meniscus and dispersing agent corrections to hydrometer reading are respectively

a)

positive and positive

b)

positive and negative

c)

negative and negative

d)

negative and positive

Q1.6

The maximum particle size for which Darcy's law is applicable is

a)

75 µm

b)

0.2 mm

c)

0.5 mm

d)

0.1 mm

Q1.7

A soil has a discharge velocity of $ 6 \times 10^{-6} \text{ m/s} $ and the porosity of 0.40. Its seepage velocity is

a)

15×106 m/s15 \times 10^{-6} \text{ m/s}

b)

1.5×106 m/s1.5 \times 10^{-6} \text{ m/s}

c)

2.4×106 m/s2.4 \times 10^{-6} \text{ m/s}

d)

6×106 m/s6 \times 10^{-6} \text{ m/s}

Q1.8

If water rises (unit weight of water = $ \gamma_w $) by a height h above the groundwater table by capillary action, the pore water pressure the height at h above groundwater table is

a)

zero

b)

γwh\gamma_w h

c)

γwh-\gamma_w h

d)

γwh2\gamma_w h^2

Q1.9

The number of blows used for compacting each layer in modified proctor test is

a)

25 blows

b)

56 blows

c)

55 blows

d)

76 blows

Q1.10

In which of the following footings of equal width, the vertical stress extends to larger depth below its base?

a)

Square footing

b)

Strip footing

c)

Circular footing

d)

Rectangular footing

Q.2 Solve both questions :

Q2.1

Distinguish clearly between physical and chemical weathering.

Q2.2

A saturated clay has a water content of 40% and a bulk specific gravity of 1.75. Determine the void ratio and specific gravity of particles. [Take unit weight of water = 10 kN/m³]

Q.3 Solve both questions :

Q3.1

Write a short note on the 'method of determination of Atterberg limits'.

Q3.2

A fully saturated clay has a water content 40% and a mass specific gravity of 1.92. After oven drying, the mass specific gravity reduces to 1.81. Determine the specific gravity of soil solids and shrinkage limit.

Q.4 Solve both questions :

Q4.1

Sketch the grain size distribution curve for uniformly graded, well-graded and gap-graded soils and discuss their Characteristics.

Q4.2

Two soils $ S_1 $ and $ S_2 $ are tested in the laboratory for the consistency limits. The data available is as follows :

Soil S1 Soil S2
Plastic limit 21% 31%
Liquid limit 61% 65%
Flow index 10 5
Natural moisture content 40% 50%

(i) Which one is more plastic? (ii) Which one is better foundation material when remoulded? (iii) Which one has better strength as a function of water content? (iv) Which one has better strength at the plastic limit?

Q.5 Solve both questions :

Q5.1

How do you determine the permeability of cohesive soils in the laboratory? Derive the formula you used.

Q5.2

A field pumping out test gave the following data : Diameter of well = 30 cm; Thickness of confined aquifer = 35 m; Radius of circle of influence = 300 m; Drawdown during the test = 5.5 m; Pump discharge = 0.9 cumecs. Compute the permeability of the aquifer.

Q.6 Solve both questions :

Q6.1

What is quick sand? How would you calculate the hydraulic gradient required to create quick sand conditions in sand?

Q6.2

A sand deposit consists of two layers. The top layer is 3.0 m thick (unit weight = 17 kN/m³) and the bottom layer is 4.0 m thick (unit weight = 18 kN/m³). The water table is at a depth of 4.0 m from the top. Draw the diagram and show the variation of total stress, neutral stress and effective stress.

Q.7 Solve both questions :

Q7.1

What are the factors that affect compaction? Discuss in detail.

Q7.2

A laboratory compaction test on the soil having specific gravity 2.70 gave an MDD of 1.85 gm/cc and a water content of 19%. Determine the degree of saturation, air content and percentage air voids at the MDD. What would be theoretical MDD corresponding to zero air voids at the OMC?

Q.8 Solve both questions :

Q8.1

Derive the equation for vertical stress due to line load of intensity q.

Q8.2

A point load of 250 kN acts on the ground surface. Using the Boussinesq analysis, find the maximum vertical pressure on the vertical plane at a distance of 3 m from the loading.

Q.9 Write short notes on any four of the following:

Q9.1
a)

Pheratic line

b)

Stress isobar

c)

Boiling sand condition

d)

Grain size analysis

e)

Sand replacement method

f)

Flow and toughness indices


2020 V4 101503

B.Tech 5th Semester Exam., 2020

Time 3 hours
Full Marks 70
Instructions:
  • The marks are indicated in the right-hand margin.
  • There are NINE questions in this paper.
  • Attempt FIVE questions in all.
  • Question No. 1 is compulsory.

Q.1 Choose the correct answer of the following (any seven) :

Q1.1

Water transported soils are termed as

a)

alluvial

b)

aeoline

c)

talus

d)

loess

Q1.2

The three-phase soil system consists of

a)

soil, water and air

b)

soil, semi-solid and air

c)

solids, water and air

d)

solids, semi-solids and water

Q1.3

The standard and most accurate method for determination of water content is

a)

calcium carbide method

b)

torsion balance method

c)

oven drying method

d)

alcohol method

Q1.4

The property of fine grained soils to change from liquid state to plastic state with decrease of water content is known as

a)

liquidity

b)

plasticity

c)

shrinkage

d)

consistency

Q1.5

The meniscus and dispersing agent corrections to hydrometer reading are respectively

a)

positive and positive

b)

positive and negative

c)

negative and negative

d)

negative and positive

Q1.6

The maximum particle size for which Darcy's law is applicable is

a)

75 µm

b)

0.2 mm

c)

0.5 mm

d)

0.1 mm

Q1.7

A soil has a discharge velocity of $ 6 \times 10^{-6} \text{ m/s} $ and the porosity of 0.40. Its seepage velocity is

a)

15×106 m/s15 \times 10^{-6} \text{ m/s}

b)

1.5×106 m/s1.5 \times 10^{-6} \text{ m/s}

c)

2.4×106 m/s2.4 \times 10^{-6} \text{ m/s}

d)

6×106 m/s6 \times 10^{-6} \text{ m/s}

Q1.8

If water rises (unit weight of water = $ \gamma_w $) by a height h above the groundwater table by capillary action, the pore water pressure the height at h above groundwater table is

a)

zero

b)

γwh\gamma_w h

c)

γwh-\gamma_w h

d)

γwh2\gamma_w h^2

Q1.9

The number of blows used for compacting each layer in modified proctor test is

a)

25 blows

b)

56 blows

c)

55 blows

d)

76 blows

Q1.10

In which of the following footings of equal width, the vertical stress extends to larger depth below its base?

a)

Square footing

b)

Strip footing

c)

Circular footing

d)

Rectangular footing

Q.2 Solve both questions :

Q2.1

Distinguish clearly between physical and chemical weathering.

Q2.2

A saturated clay has a water content of 40% and a bulk specific gravity of 1.75. Determine the void ratio and specific gravity of particles. [Take unit weight of water = 10 kN/m³]

Q.3 Solve both questions :

Q3.1

Write a short note on the 'method of determination of Atterberg limits'.

Q3.2

A fully saturated clay has a water content 40% and a mass specific gravity of 1.92. After oven drying, the mass specific gravity reduces to 1.81. Determine the specific gravity of soil solids and shrinkage limit.

Q.4 Solve both questions :

Q4.1

Sketch the grain size distribution curve for uniformly graded, well-graded and gap-graded soils and discuss their Characteristics.

Q4.2

Two soils $ S_1 $ and $ S_2 $ are tested in the laboratory for the consistency limits. The data available is as follows :

Soil S1 Soil S2
Plastic limit 21% 31%
Liquid limit 61% 65%
Flow index 10 5
Natural moisture content 40% 50%

(i) Which one is more plastic? (ii) Which one is better foundation material when remoulded? (iii) Which one has better strength as a function of water content? (iv) Which one has better strength at the plastic limit?

Q.5 Solve both questions :

Q5.1

How do you determine the permeability of cohesive soils in the laboratory? Derive the formula you used.

Q5.2

A field pumping out test gave the following data : Diameter of well = 30 cm; Thickness of confined aquifer = 35 m; Radius of circle of influence = 300 m; Drawdown during the test = 5.5 m; Pump discharge = 0.9 cumecs. Compute the permeability of the aquifer.

Q.6 Solve both questions :

Q6.1

What is quick sand? How would you calculate the hydraulic gradient required to create quick sand conditions in sand?

Q6.2

A sand deposit consists of two layers. The top layer is 3.0 m thick (unit weight = 17 kN/m³) and the bottom layer is 4.0 m thick (unit weight = 18 kN/m³). The water table is at a depth of 4.0 m from the top. Draw the diagram and show the variation of total stress, neutral stress and effective stress.

Q.7 Solve both questions :

Q7.1

What are the factors that affect compaction? Discuss in detail.

Q7.2

A laboratory compaction test on the soil having specific gravity 2.70 gave an MDD of 1.85 gm/cc and a water content of 19%. Determine the degree of saturation, air content and percentage air voids at the MDD. What would be theoretical MDD corresponding to zero air voids at the OMC?

Q.8 Solve both questions :

Q8.1

Derive the equation for vertical stress due to line load of intensity q.

Q8.2

A point load of 250 kN acts on the ground surface. Using the Boussinesq analysis, find the maximum vertical pressure on the vertical plane at a distance of 3 m from the loading.

Q.9 Write short notes on any four of the following:


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