Q.1) The soil transported by wind is called –
A) Lacustrine soil
B) Aeolian soil
C) Alluvial soil
D) Marine soil
Option (B)
Explanation :
Aeolian deposit – transported by wind
Marine deposit – deposited by sea water
Lacustrine deposit – deposited by still water like lakes.
Alluvial deposit – deposited by river water
Glacial deposit – transported by ice
Colluvial soil – deposited by gravity
Q.2) Black cotton soil is a product of decomposition of –
A) Marble
B) Granite
C) Basalt
D) Sandstone
Option (C)
Explanation :
Nil.
Q.3) The degree of compaction for sand is usually defined in terms of :
A) Standard Proctor Test
B) Relative Density
C) Modified Proctor Test
D) Nuclear Density Meter
Option (B)
Explanation :
Relative density is used to express the relative compactness (or degree of compaction) of natural cohesionless soil deposit.
Q.4) A soil sample has a porosity of 40% and G = 2.7. If the soil is 50% saturated, the unit weight will be nearly :
A) 20 kN/m3
B) 18 kN/m3
C) 22 kN/m3
D) 16 kN/m3
Option (B)
Explanation :
Void ratio, e = n/(1-n) = 0.4/(1-0.4) = 2/3 = 0.67
Unit weight, Υ = [(G + S*e)/(1 + e)] * Υw
Υ = [(2.7 + 0.5*0.67)/(1+0.67)] * 9.81 = 17.85 kN/m3 ≅ 18 kN/m3
Q.5) For naturally deposited clay, the ratio of unconfined compressive strength in undisturbed state to that in remoulded state is called :
A) Degree of saturation
B) Degree of compaction
C) Degree of sensitivity
D) Degree of thixotrophy
Option (C)
Explanation :
Degree of saturation : It refers to the amount of water present in a soil relative to the total amount of pore space in the soil. It is stated as a percentage, with 100% saturation indicating that water has filled every soil pore space. The degree of saturation plays a significant role in defining the strength and permeability of soil, among other physical characteristics.
Degree of compaction : The term “degree of compaction” describes how much a soil has been squeezed or compacted in order to lower its volume and increase its density. Usually, mechanical methods like the usage of large machinery or roller compaction are used to accomplish this. The strength, capacity to hold weight, and capacity to enable water to drain through the soil can all be impacted by the degree of compaction.
Degree of sensitivity : It refers to the extent to which a soil changes its physical properties, such as its strength and deformation, in response to changes in water content. Soils with a high degree of sensitivity are more prone to changes in their physical properties due to changes in water content, while soils with a low degree of sensitivity are less affected.
Degree of thixotrophy : The ability of a soil to alter its consistency in response to variations in shear stress is referred to as degree of thixotrophy. When undergoing shear stress, thixotropic soils become more fluid before reverting to their initial state. This may have an impact on the stability of slopes and other buildings as well as the simplicity of excavation and compaction in specific soil types.
Q.6) Which of the following method is most accurate for the determination of the water content of soil :
A) Calcium Carbide Method
B) Pycnometer Method
C) Sand Bath Method
D) Oven Drying Method
Option (D)
Explanation :
Methods of determining water content in soil :
- Oven drying method
- Sand bath method
- Calcium carbide method
- Pycnometer method
- Torsional balance method
- Radiation method
Q.7) Which of the following clay mineral gives maximum swelling?
A) illite
B) kaolinite
C) montmorillonite
D) vermiculite
Option (C)
Explanation :
Nil.
Q.8) A strata of 3.5 m thick fine sand has a void ratio of 0.7 and G = 2.7. Find a quick sand condition to develop in this strata, the water flowing in upward direction would require a head of –
A) 6 m
B) 5 m
C) 3.5 m
D) 4 m
Option (C)
Explanation :
ic = (G – 1)/(1 + e) = (2.7 – 1)/(1 + 0.7) = 1
ic = h/l
1 = h/3.5
h = 3.5 m
Q.9) Sheep foot rollers are suitable for compacting :
A) sand and gravels only
B) all fine-grained material
C) semi-cohesive soils
D) all types of soils except sand
Option (B)
Explanation :
Nil.
Q.10) The pressure which is exerted by water on the soil through which it percolates, is called :
A) Seepage pressure
B) Active earth pressure
C) Passive earth pressure
D) Surface tension
Option (A)
Explanation :
Seepage pressure is the amount of water that is forced out of soil pores or rock pores by the hydrostatic pressure of the groundwater in the vicinity.
Q.11) Hygroscopic water is defined as the –
A) water which is adsorbed by the particles of the dry soil from the atmosphere
B) water held by the soil under capillary action
C) readily available water for the use of plants
D) total water content of the soil when all pores are filled with water
Option (A)
Explanation :
Water that is retained in the pores of soil and other geomaterials is referred to as hygroscopic water. Because it rapidly collects moisture from the air around it, as well as from precipitation and other sources, this form of water is regarded as being hygroscopic.
The behaviour and performance of soil and other geomaterials can be significantly impacted by the presence of hygroscopic water in geotechnical engineering.
Hygroscopic water, for instance, can cause soil to swell, which can modify the soil’s volume and stability. When designing and building foundations and retaining walls, where changes in soil volume can result in severe stress and settlement, this can be extremely problematic.
Q.12) The value of compression index for a remoulded sample whose liquid limit is 40% is :
A) 0.021
B) 0.21
C) 0.002
D) 0.3
Option (B)
Explanation :
Compression index, Cc = 0.007 (wL – 10)
Cc = 0.007 (40 – 10) = 0.21
Q.13) Oedometer is used to calculate which of the following soil parameter :
A) Particle size analysis
B) Permeability
C) Compressibility
D) Specific gravity
Option (C)
Explanation :
Oedometer is used to determine the compression behavior of soil samples. It is a vertical-loading apparatus that applies a vertical stress to a soil sample and measures the corresponding compression. The compression is usually measured either by observing the displacement of the soil sample or by measuring the change in volume of the soil sample. The oedometer test provides information on the compression behavior of soil and the parameters that control soil deformation, such as soil compressibility and shear strength.
Q.14) The objective of consolidation test is –
A) to determine degree of saturation
B) to determine moisture content
C) to determine coefficient of compressibility
D) to determine OMC and MDD
Option (C)
Explanation :
Consolidation test is used to ascertain the compression behaviour of soil under gradually increasing load over time. In order to properly construct foundations, slopes, retaining walls, and other soil-based structures, the test offers information regarding the compression and swelling properties of soil.
The consolidation test is performed in a laboratory setting using a specialized device known as a consolidometer. The soil sample is placed in the consolidometer, and a load is applied to the soil in increments over a period of time. The amount of compression or settlement that occurs under each increment of load is measured, and the data is used to construct a compression curve, which shows the relationship between the applied load and the compression or settlement.
Engineers can calculate the coefficient of compression, which is a measure of the overall compression that will occur under a particular load, and the compression index, which is a measure of the rate of compression, from the compression curve. These numbers offer crucial details regarding the soil’s compressibility and its capacity to sustain loads over time.
Q.15) The general Boussinesq equations for determining stress below soil considers :
A) cyclic load
B) uniformly distributed load
C) uniformly varying load
D) concentrated load
Option (D)
Explanation :
Nil.
Q.16) The phenomenon when soil loses its shear strength due to oscillatory motion is known as :
A) Liquefaction
B) Consolidation
C) Shear failure
D) Sloughing
Option (A)
Explanation :
Liquefaction: Liquefaction is a phenomenon that occurs in certain types of soil causing the soil to behave like a liquid instead of a solid. Liquefaction is caused by the rapid increase in pore water pressure in the soil due to the shaking caused by an earthquake.
Consolidation: Consolidation is the process by which soil compacts and shrinks in volume as a result of an increasing load applied over time. Consolidation is caused by the expulsion of excess water from soil pores and plays an important role in soil behaviour and the long-term settlement of structures built on soil. Laboratory consolidation tests are used to determine the compressibility of soil and the rate at which it will settle under a given load.
Shear failure: Shear failure is the failure of soil or rock due to sliding or slipping along a plane of weakness. Shear failure is a common cause of slope instability and can occur in both natural and man-made slopes.
Sloughing: Sloughing is the sudden and rapid movement of soil down a slope, typically due to the failure of the soil’s cohesion or the shear strength of the soil.
Q.17) In-situ vane shear test is conducted to determine the shear strength of :
A) silty soil
B) cohesive soil
C) non-cohesive soil
D) sandy soil
Option (B)
Explanation :
The vane shear test is an in-situ laboratory test used to determine the shear strength of cohesive soils. It measures the shear resistance of soil along a vertical plane.
The vane shear test is a relatively quick and simple test, and provides information about the shear strength of soil that is useful in the design of retaining walls, slopes, and other structures built on or within soil.
Q.18) Which of the following test is not used to measure the shear strength of soil?
A) Unconfined Compression Test
B) Triaxial Compression Test
C) Vane Shear Test
D) Standard Prcotor Test
Option (D)
Explanation :
Standard Proctor Test is used to determine OMC and MDD of soil sample.
Q.19) Coulomb’s theory of earth pressure is based on –
A) The theory of elasticity
B) Empirical rules
C) The theory of plasticity
D) Wedge theory
Option (D)
Explanation :
Nil.
Q.20) For foundation of clayey soil, the maximum differential settlement in limited –
A) 30 mm
B) 20 mm
C) 50 mm
D) 40 mm
Option (D)
Explanation :
As per IS: 1904-1966, differential settlement limits for,
Clay soil = 40 mm
Sandy soil = 25 mm
