50 MCQ questions on Soil Mechanics & Foundation Engineering
Soil Types & Classification
-
The soil which contains a high proportion of silt and clay is called:
-
a) Gravel
-
b) Loam
-
c) Cohesive soil
-
d) Sandy soil
✅ Ans: c
-
-
The grain size of clay is:
-
a) More than 4.75 mm
-
b) 0.075 – 4.75 mm
-
c) 0.002 – 0.075 mm
-
d) Less than 0.002 mm
✅ Ans: d
-
-
Which method is used for particle size distribution in fine-grained soils?
-
a) Sieve analysis
-
b) Hydrometer analysis
-
c) Casagrande method
-
d) Atterberg limits
✅ Ans: b
-
-
Which of the following is not a soil classification system?
-
a) Unified Soil Classification System
-
b) Indian Standard Soil Classification System
-
c) Highway Research Board System
-
d) Harvard Classification
✅ Ans: d
-
-
Plasticity Index is given by:
-
a) LL – PL
-
b) PL – LL
-
c) SL – PL
-
d) LL + PL
✅ Ans: a
-
-
A soil is called highly plastic if its PI is:
-
a) < 7%
-
b) 7%–17%
-
c) > 17%
-
d) 0%
✅ Ans: c
-
-
Liquidity index (LI) is used to express:
-
a) Consistency of liquid
-
b) Water content
-
c) Relative consistency of cohesive soil
-
d) Specific gravity
✅ Ans: c
-
-
Which of the following is a clay mineral?
-
a) Feldspar
-
b) Illite
-
c) Quartz
-
d) Calcite
✅ Ans: b
-
-
The term “bulking of sand” refers to:
-
a) Increase in volume due to compaction
-
b) Decrease in volume due to moisture
-
c) Increase in volume due to moisture
-
d) None
✅ Ans: c
-
-
Highly compressible clay is represented by:
-
a) CH
-
b) CL
-
c) ML
-
d) MH
✅ Ans: a
2. Permeability & Seepage
-
Permeability depends on:
-
a) Soil type
-
b) Void ratio
-
c) Degree of saturation
-
d) All of the above
✅ Ans: d
-
Darcy’s law is valid for:
-
a) Laminar flow
-
b) Turbulent flow
-
c) Both
-
d) None
✅ Ans: a
-
Unit of permeability is:
-
a) m/s
-
b) m³/s
-
c) m²/s
-
d) m
✅ Ans: a
-
Coefficient of permeability is more for:
-
a) Clay
-
b) Silt
-
c) Gravel
-
d) Loam
✅ Ans: c
-
Seepage pressure is:
-
a) Effective stress
-
b) Pore pressure
-
c) Water pressure
-
d) Pressure exerted by seepage
✅ Ans: d
-
Flow net consists of:
-
a) Equipotential lines and streamlines
-
b) Isobars and contours
-
c) Only streamlines
-
d) None
✅ Ans: a
-
In isotropic soil, flow net forms:
-
a) Squares
-
b) Rectangles
-
c) Parabolas
-
d) Circles
✅ Ans: a
-
For stratified soils, equivalent permeability in vertical direction is:
-
a) Arithmetic mean
-
b) Geometric mean
-
c) Harmonic mean
-
d) Weighted mean
✅ Ans: c
-
Quick sand condition is achieved when:
-
a) Effective stress becomes zero
-
b) Total stress is zero
-
c) Permeability is high
-
d) Soil is dry
✅ Ans: a
-
Seepage force acts in:
-
a) Upward direction
-
b) Downward direction
-
c) Perpendicular to flow
-
d) Horizontal only
✅ Ans: a
3. Compaction
-
Compaction is the process of:
-
a) Increasing water content
-
b) Reducing voids
-
c) Increasing particle size
-
d) None
✅ Ans: b
-
Standard Proctor Test is used to determine:
-
a) Liquid limit
-
b) Field density
-
c) OMC & MDD
-
d) Permeability
✅ Ans: c
-
Optimum moisture content is the moisture at:
-
a) Max dry density
-
b) Min void ratio
-
c) Min dry density
-
d) Max permeability
✅ Ans: a
-
Dry density increases with:
-
a) Decrease in compaction
-
b) Increase in water content (up to OMC)
-
c) Decrease in water content
-
d) None
✅ Ans: b
-
Zero air void line represents:
-
a) Maximum density
-
b) Fully saturated condition
-
c) No water
-
d) Air dry soil
✅ Ans: b
-
Compactive effort in Modified Proctor Test is:
-
a) Less than Standard
-
b) More than Standard
-
c) Equal
-
d) None
✅ Ans: b
-
Compaction increases:
-
a) Shear strength
-
b) Permeability
-
c) Compressibility
-
d) All
✅ Ans: a
-
Field compaction is measured by:
-
a) Proctor test
-
b) Plate load test
-
c) Core cutter & sand replacement
-
d) Vane shear test
✅ Ans: c
-
For clayey soils, best compaction is achieved using:
-
a) Smooth roller
-
b) Pneumatic roller
-
c) Sheep foot roller
-
d) Vibratory roller
✅ Ans: c
-
Relative compaction is:
-
a) Field/Max density × 100
-
b) Min/Max density
-
c) Field/Moisture content
-
d) OMC/Field density
✅ Ans: a
4. Bearing Capacity
-
Ultimate bearing capacity is:
-
a) Max pressure soil can withstand
-
b) Pressure at failure
-
c) Safe load
-
d) a & b
✅ Ans: d
-
Safe bearing capacity is:
-
a) Ultimate load divided by FOS
-
b) Total load
-
c) Allowable load
-
d) None
✅ Ans: a
-
Terzaghi’s bearing capacity theory is for:
-
a) Square footing
-
b) Strip footing
-
c) Circular footing
-
d) Raft footing
✅ Ans: b
-
Bearing capacity increases with:
-
a) Water table rise
-
b) Larger footing width
-
c) Loose soil
-
d) Over consolidation
✅ Ans: b
-
Bearing capacity of sandy soil is governed by:
-
a) Cohesion
-
b) Internal friction
-
c) Water table
-
d) Surcharge
✅ Ans: b
-
Factor of safety in bearing capacity is usually:
-
a) 1.0
-
b) 1.5
-
c) 2.5–3
-
d) 10
✅ Ans: c
-
Gross bearing capacity includes:
-
a) Self-weight
-
b) Weight of footing
-
c) Overburden pressure
-
d) All
✅ Ans: d
-
Effect of water table near footing is:
-
a) Increase in bearing capacity
-
b) Decrease in bearing capacity
-
c) No effect
-
d) Depends on soil
✅ Ans: b
-
In saturated clay, bearing capacity is determined by:
-
a) Terzaghi's formula
-
b) Unconfined compression test
-
c) SPT
-
d) None
✅ Ans: b
-
For shallow foundations, depth of foundation is usually:
-
a) < width
-
b) > width
-
c) Equal to width
-
d) 1.5× width
✅ Ans: a
5. Earth Pressure Theories
-
Rankine’s theory assumes:
-
a) Wall is frictionless
-
b) Backfill is dry
-
c) Back of wall is vertical
-
d) All
✅ Ans: d
-
Earth pressure at rest occurs when:
-
a) Wall moves away
-
b) Wall moves toward backfill
-
c) No movement
-
d) Wall is inclined
✅ Ans: c
-
Active earth pressure is:
-
a) More than passive
-
b) Less than passive
-
c) Equal
-
d) Zero
✅ Ans: b
-
Earth pressure increases with:
-
a) Height of wall
-
b) Surcharge
-
c) Unit weight of soil
-
d) All
✅ Ans: d
-
Coefficient of active earth pressure for cohesionless soil:
-
a) (1+sin φ)/(1−sin φ)
-
b) (1−sin φ)/(1+sin φ)
-
c) tan²(45°+φ/2)
-
d) None
✅ Ans: b
6. Types of Foundations
-
Raft foundation is preferred when:
-
a) Soil has low bearing capacity
-
b) Heavy column loads
-
c) Differential settlement is to be avoided
-
d) All
✅ Ans: d
-
Shallow foundation is used when:
-
a) Soil near surface is strong
-
b) Load is light
-
c) Depth < width
-
d) All
✅ Ans: d
-
Pile foundations are used when:
-
a) Hard strata is deep
-
b) Heavy loads
-
c) Marshy area
-
d) All
✅ Ans: d
-
End bearing piles transfer load through:
-
a) Skin friction
-
b) Point resistance
-
c) Both
-
d) None
✅ Ans: b
-
Caisson is a type of:
-
a) Shallow foundation
-
b) Well foundation
-
c) Pile
-
d) None
✅ Ans: b