All Free Civil Engineering MCQs with Answers
Every Civil Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
631 questions · page 20 of 32
- A. Expulsion of air from soil voids
- B. Breakage of soil particles
- C. Expulsion of water from soil voids
- D. Thermal expansion of pore water
Explanation: Primary consolidation involves the gradual dissipation of excess pore-water pressure and the associated expulsion of water from the voids.
Correct answer: Expulsion of water from soil voids- A. Stress versus strain curve
- B. Shear stress versus displacement curve
- C. Water content versus dry density curve
- D. Void ratio versus logarithm of effective stress curve
Explanation: The compression index is the magnitude of the slope of the virgin compression line on a plot of void ratio against logarithm of effective…
Correct answer: Void ratio versus logarithm of effective stress curve- A. During both consolidation and shearing
- B. Only during specimen saturation
- C. Only after the specimen reaches failure
- D. During neither consolidation nor shearing
Explanation: In a consolidated drained test, water is allowed to drain during consolidation and throughout shearing.
Correct answer: During both consolidation and shearing- A. Decreases because cohesion becomes zero
- B. Increases because the effective unit weight increases
- C. Remains unchanged for every soil
- D. Becomes independent of footing width
Explanation: Lowering the water table reduces buoyant effects and increases the effective unit weight contributing to bearing resistance.
Correct answer: Increases because the effective unit weight increases- A. The entire base remains uniformly compressed
- B. The soil cohesion becomes equal to zero
- C. Part of the base may lose contact with the soil
- D. The footing automatically behaves as a pile
Explanation: An eccentric load produces a nonuniform contact pressure, and excessive eccentricity can cause part of the footing base to separate from…
Correct answer: Part of the base may lose contact with the soil- A. Loose clean sand above the water table
- B. Uniform gravel with negligible volume change
- C. Hard rock with no weathered zone
- D. Expansive clay subject to seasonal movement
Explanation: Under-reamed piles have enlarged bulbs that are placed below the active zone of expansive soil, reducing the effects of seasonal swelling…
Correct answer: Expansive clay subject to seasonal movement- A. 20 percent
- B. 40 percent
- C. 60 percent
- D. 80 percent
Explanation: Degree of saturation is the fraction of void space filled with water. Therefore, the air-filled fraction is 1 minus 0.60, or 40 percent.
Correct answer: 40 percent- A. Inorganic silt
- B. Inorganic clay
- C. Organic silt
- D. Clean sand
Explanation: The A-line separates most inorganic clays from silts on the plasticity chart.
Correct answer: Inorganic clay- A. 0.40
- B. 0.60
- C. 0.67
- D. 1.67
Explanation: The volume of voids is 0.020 minus 0.012, which equals 0.008 cubic metres.
Correct answer: 0.67- A. An increase in soil particle volume
- B. A decrease in effective stress
- C. A constant total stress increase
- D. An increase in effective stress
Explanation: Under constant total stress, dissipation of excess pore pressure causes effective stress to increase.
Correct answer: An increase in effective stress- A. Effective stresses only
- B. Total stresses only
- C. Water content values only
- D. Dry density values only
Explanation: Pore pressure measurement allows the effective principal stresses to be calculated from the total stresses.
Correct answer: Effective stresses only- A. Soil self-weight
- B. Soil cohesion
- C. Footing surcharge
- D. Water pressure
Explanation: The term cNc contains the cohesion c and the bearing capacity factor Nc.
Correct answer: Soil cohesion- A. The soil has no groundwater
- B. A single column carries no load
- C. Two columns are sufficiently close together
- D. The foundation is placed on solid rock only
Explanation: A combined footing supports two or more columns on one slab or base. It is especially useful when columns are close together or when a…
Correct answer: Two columns are sufficiently close together- A. Replace the need for reinforcement
- B. Increase the permeability of soil
- C. Prevent all pile settlement
- D. Distribute column load to the piles
Explanation: A pile cap connects the pile heads and distributes the structural load among them.
Correct answer: Distribute column load to the piles- A. Increase by the same amount
- B. Decrease by the same amount
- C. Remain unchanged
- D. Become equal to pore pressure
Explanation: Effective stress equals total stress minus pore-water pressure. If pore pressure remains constant, an increase in total stress produces an…
Correct answer: Increase by the same amount- A. Local shear failure
- B. General shear failure
- C. Punching shear failure
- D. Tensile splitting failure
Explanation: Dense sand tends to dilate and develops a well-defined failure surface, which is characteristic of general shear failure.
Correct answer: General shear failure- A. m + r = 2j
- B. m + r = 3j
- C. m + 2r = 2j
- D. 2m + r = 3j
Explanation: For a stable plane truss, the number of member forces and support reactions equals the available joint equilibrium equations when m + r =…
Correct answer: m + r = 2j- A. Equal to the support reaction
- B. Always zero
- C. Equal to the shear force
- D. Equal to the axial force
Explanation: An internal hinge permits rotation and cannot transmit bending moment, so the bending moment at its location is zero.
Correct answer: Always zero- A. Both members carry equal tension
- B. One member carries the full joint load
- C. Both members are zero-force members
- D. Both members carry equal compression
Explanation: The joint has no external load, and the two member forces act in different directions.
Correct answer: Both members are zero-force members- A. Integral of EI multiplied by Mm dx
- B. Integral of M plus m over EI dx
- C. Integral of M divided by mEI dx
- D. Integral of Mm over EI dx
Explanation: The bending contribution to displacement is obtained from the integral of Mm divided by EI over the beam length.
Correct answer: Integral of Mm over EI dx