Engineering Questions with Answers - Multiple Choice Questions
Consolidation Process – 1
1 - Question
The decrease in the volume of soil mass under stress is known as __________
a) compression
b) compressibility
c) tension
d) consolidation
View Answer
Answer: a
Explanation: When a compressive load is applied to a soil mass, a decrease in its volume takes place. The decrease in volume of soil mass under stress is known as compression.
2 - Question
The property of soil mass pertaining to its susceptibility to decrease in volume under pressure is ____________
a) compression
b) compressibility
c) tension
d) consolidation
View Answer
Answer: b
Explanation: When a compressive load is applied to a soil mass, a decrease in its volume takes place. The decrease in volume of soil mass under stress is known as compression and the property of soil mass pertaining to its susceptibility to decrease in volume under pressure is compressibility.
3 - Question
Every process involving a decrease in the water content of a saturated soil without replacement of water by air is called _________
a) compression
b) compressibility
c) tension
d) consolidation
View Answer
Answer: d
Explanation: According to Terzaghi, every process involving a decrease in the water content of a saturated soil without replacement of water by air is the process of consolidation.
4 - Question
When stress is applied to soil mass, the elastic deformation of solid particles is ____________
a) extremely large
b) large
c) small
d) negligibly small
View Answer
Answer: d
Explanation: When stress is applied to soil mass, the elastic deformation of solid particles is negligibly small compared to the deformation caused by change in relative position of the discrete particles and the resulting decrease in the volume of voids.
5 - Question
The compression resulting from a long term static load and consequent escape of pore water is _____________
a) compression
b) compressibility
c) tension
d) consolidation
View Answer
Answer: d
Explanation: The compression resulting from a long term static load and consequent escape of pore water is consolidation, as according to Terzaghi, every process involving a decrease in the water content of a saturated soil without replacement of water by air is the process of consolidation.
6 - Question
If increases in the water content due to an increase in the volume of voids is known as _________
a) compression
b) compressibility
c) swelling
d) consolidation
View Answer
Answer: c
Explanation: Swelling is the increase in the water content due to an increase in the volume of voids. According to Terzaghi, it is the opposite of consolidation. Consolidation is decrease in the water content of a saturated soil without replacement of water by air.
7 - Question
Compression of soil, under short duration of moving or vibratory loads is _________
a) saturation
b) compressibility
c) swelling
d) compaction
View Answer
Answer: d
Explanation: Compression of soil, under short duration of moving or vibratory loads is known as compaction. Swelling is the increase in the water content due to an increase in the volume of voids. The compression resulting from a long term static load and consequent escape of pore water is consolidation.
8 - Question
Slow vertical deformation occurs when a compressive load is applied to a laterally confined layer of sand.
a) True
b) False
View Answer
Answer: b
Explanation: When a compressive load is applied to a laterally confined layer of sand, rapid vertical deformation occurs. The rate at which this deformation can take place depends upon the permeability of soil and upon the distance the water must travel to reach a drainage surface.
9 - Question
The compressibility of clays may also be caused by the following factor.
a) changes in salinity
b) ion exchange
c) expulsion of double layer water from between the grains
d) swelling of clay
View Answer
Answer: c
Explanation: The compressibility of clays may also be caused by the three factors:
I. expulsion of double layer water from between the grains
II. slipping of particles to new positions of greater density
III. bending of particles as elastic sheets
10 - Question
The mechanics of consolidation was demonstrated by ___________
a) Taylor
b) Skempton
c) Terzaghi
d) Darcy
View Answer
Answer: c
Explanation: The mechanics of consolidation was demonstrated by Terzaghi, by means of the piston and spring analogy.
11 - Question
In the spring analogy of consolidation, cylinder is filled with water up to bottom of piston and spring carries 10 units of load. If external two units of load is applied and the valve closed, then the effective pressure σ’ and hydrodynamic pressure u is given by ___________
a) σ’=0, u=12
b) σ’=0, u=0
c) σ’=10, u=2
d) σ’=12, u=0
View Answer
Answer: c
Explanation: When external two units of load is applied and the valve closed, then the effective pressure σ’ and hydrodynamic pressure u is given by σ’=10, u=2. This is because the additional pressure of 2 units is entirely borne by water.
12 - Question
In the spring analogy of consolidation, cylinder is filled with water up to bottom of piston and spring carries 10 units of load. If external two units of load is applied and the valve is partly opened, then the effective pressure σ’ and hydrodynamic pressure u is given by ___________
a) σ’=0, u=12
b) σ’=10+∆σ’, u=2-∆σ’
c) σ’=10, u=2
d) σ’=12, u=0
View Answer
Answer: b
Explanation: When external two units of load is applied and the valve is partly opened, then the effective pressure σ’ and hydrodynamic pressure u is given by σ’=10+∆σ’, u=2-∆σ’. This is because the additional pressure of 2 units is borne both by spring as well as water.
13 - Question
In the spring analogy of consolidation, cylinder is filled with water up to bottom of piston and spring carries 10 units of load. If external two units of load is applied and the valve is opened, then the effective pressure σ’ and hydrodynamic pressure u is given by ___________
a) σ’=0, u=12
b) σ’=10+∆σ’, u=2-∆σ’
c) σ’=10, u=2
d) σ’=12, u=0
View Answer
Answer: d
Explanation: When external two units of load is applied and the valve is opened, then the effective pressure σ’ and hydrodynamic pressure u is given by σ’=12, u=0. This is because the additional pressure of 2 units is borne by water is entirely transferred to the spring.
14 - Question
Excess pore pressure is also known as ___________
a) hydrodynamic pressure
b) seepage pressure
c) effective pressure
d) total pressure
View Answer
Answer: a
Explanation: The pressure that builds up in pore water due to load increment in the soil is termed as excess pore pressure. Excess pore pressure is also known as excess hydrostatic pressure or hydrodynamic pressure.
15 - Question
In fluid flow calculations, water is considered as incompressible.
a) True
b) False
View Answer
Answer: a
Explanation: Water is slightly compressible but in fluid flow calculations, water is considered as incompressible because the pressure changes involved are too small to make appreciable change to the density.