50 MCQ questions on Soil Mechanics & Foundation Engineering for JKSSB JE CIVIL SSC JE RRB JE Civil engineer

 50 MCQ questions on Soil Mechanics & Foundation Engineering

Soil Types & Classification

1. 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

2. 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

3. 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

4. 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

5. Plasticity Index is given by:

   • a) LL – PL

   • b) PL – LL

   • c) SL – PL

   • d) LL + PL
     ✅ Ans: a

6. A soil is called highly plastic if its PI is:

   • a) < 7%

   • b) 7%–17%

   • c) > 17%

   • d) 0%
     ✅ Ans: c

7. 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

8. Which of the following is a clay mineral?

   • a) Feldspar

   • b) Illite

   • c) Quartz

   • d) Calcite
     ✅ Ans: b

9. 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

10. Highly compressible clay is represented by:

• a) CH

• b) CL

• c) ML

• d) MH
  ✅ Ans: a

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2. Permeability & Seepage

11. Permeability depends on:

• a) Soil type

• b) Void ratio

• c) Degree of saturation

• d) All of the above
  ✅ Ans: d

12. Darcy’s law is valid for:

• a) Laminar flow

• b) Turbulent flow

• c) Both

• d) None
  ✅ Ans: a

13. Unit of permeability is:

• a) m/s

• b) m³/s

• c) m²/s

• d) m
  ✅ Ans: a

14. Coefficient of permeability is more for:

• a) Clay

• b) Silt

• c) Gravel

• d) Loam
  ✅ Ans: c

15. Seepage pressure is:

• a) Effective stress

• b) Pore pressure

• c) Water pressure

• d) Pressure exerted by seepage
  ✅ Ans: d

16. Flow net consists of:

• a) Equipotential lines and streamlines

• b) Isobars and contours

• c) Only streamlines

• d) None
  ✅ Ans: a

17. In isotropic soil, flow net forms:

• a) Squares

• b) Rectangles

• c) Parabolas

• d) Circles
  ✅ Ans: a

18. For stratified soils, equivalent permeability in vertical direction is:

• a) Arithmetic mean

• b) Geometric mean

• c) Harmonic mean

• d) Weighted mean
  ✅ Ans: c

19. 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

20. Seepage force acts in:

• a) Upward direction

• b) Downward direction

• c) Perpendicular to flow

• d) Horizontal only
  ✅ Ans: a

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3. Compaction

21. Compaction is the process of:

• a) Increasing water content

• b) Reducing voids

• c) Increasing particle size

• d) None
  ✅ Ans: b

22. Standard Proctor Test is used to determine:

• a) Liquid limit

• b) Field density

• c) OMC & MDD

• d) Permeability
  ✅ Ans: c

23. Optimum moisture content is the moisture at:

• a) Max dry density

• b) Min void ratio

• c) Min dry density

• d) Max permeability
  ✅ Ans: a

24. 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

25. Zero air void line represents:

• a) Maximum density

• b) Fully saturated condition

• c) No water

• d) Air dry soil
  ✅ Ans: b

26. Compactive effort in Modified Proctor Test is:

• a) Less than Standard

• b) More than Standard

• c) Equal

• d) None
  ✅ Ans: b

27. Compaction increases:

• a) Shear strength

• b) Permeability

• c) Compressibility

• d) All
  ✅ Ans: a

28. Field compaction is measured by:

• a) Proctor test

• b) Plate load test

• c) Core cutter & sand replacement

• d) Vane shear test
  ✅ Ans: c

29. For clayey soils, best compaction is achieved using:

• a) Smooth roller

• b) Pneumatic roller

• c) Sheep foot roller

• d) Vibratory roller
  ✅ Ans: c

30. Relative compaction is:

• a) Field/Max density × 100

• b) Min/Max density

• c) Field/Moisture content

• d) OMC/Field density
  ✅ Ans: a

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4. Bearing Capacity

31. Ultimate bearing capacity is:

• a) Max pressure soil can withstand

• b) Pressure at failure

• c) Safe load

• d) a & b
  ✅ Ans: d

32. Safe bearing capacity is:

• a) Ultimate load divided by FOS

• b) Total load

• c) Allowable load

• d) None
  ✅ Ans: a

33. Terzaghi’s bearing capacity theory is for:

• a) Square footing

• b) Strip footing

• c) Circular footing

• d) Raft footing
  ✅ Ans: b

34. Bearing capacity increases with:

• a) Water table rise

• b) Larger footing width

• c) Loose soil

• d) Over consolidation
  ✅ Ans: b

35. Bearing capacity of sandy soil is governed by:

• a) Cohesion

• b) Internal friction

• c) Water table

• d) Surcharge
  ✅ Ans: b

36. Factor of safety in bearing capacity is usually:

• a) 1.0

• b) 1.5

• c) 2.5–3

• d) 10
  ✅ Ans: c

37. Gross bearing capacity includes:

• a) Self-weight

• b) Weight of footing

• c) Overburden pressure

• d) All
  ✅ Ans: d

38. 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

39. In saturated clay, bearing capacity is determined by:

• a) Terzaghi's formula

• b) Unconfined compression test

• c) SPT

• d) None
  ✅ Ans: b

40. For shallow foundations, depth of foundation is usually:

• a) < width

• b) > width

• c) Equal to width

• d) 1.5× width
  ✅ Ans: a

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5. Earth Pressure Theories

41. Rankine’s theory assumes:

• a) Wall is frictionless

• b) Backfill is dry

• c) Back of wall is vertical

• d) All
  ✅ Ans: d

42. Earth pressure at rest occurs when:

• a) Wall moves away

• b) Wall moves toward backfill

• c) No movement

• d) Wall is inclined
  ✅ Ans: c

43. Active earth pressure is:

• a) More than passive

• b) Less than passive

• c) Equal

• d) Zero
  ✅ Ans: b

44. Earth pressure increases with:

• a) Height of wall

• b) Surcharge

• c) Unit weight of soil

• d) All
  ✅ Ans: d

45. 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

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6. Types of Foundations

46. 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

47. Shallow foundation is used when:

• a) Soil near surface is strong

• b) Load is light

• c) Depth < width

• d) All
  ✅ Ans: d

48. Pile foundations are used when:

• a) Hard strata is deep

• b) Heavy loads

• c) Marshy area

• d) All
  ✅ Ans: d

49. End bearing piles transfer load through:

• a) Skin friction

• b) Point resistance

• c) Both

• d) None
  ✅ Ans: b

50. Caisson is a type of:

• a) Shallow foundation

• b) Well foundation

• c) Pile

• d) None
  ✅ Ans: b