ME or MEng Master of Engineering Master of Civil Engineering 2 — Questions and Answers
Question 1: In retaining wall design, what is the primary purpose of a drainage layer or weep holes?
- To increase wall height capacity
- To relieve hydrostatic pressure behind the wall (Correct answer)
- To improve aesthetic appearance
- To prevent frost heave at the base
Correct answer: To relieve hydrostatic pressure behind the wall
Drainage layers and weep holes relieve hydrostatic pressure that would otherwise add significant lateral force to the retained soil pressure.
Question 2: The Hazen-Williams equation is used to calculate:
- Soil permeability in saturated flow
- Head loss due to friction in pressurized pipe flow (Correct answer)
- Wave runup on coastal structures
- Settlement of cohesive soils
Correct answer: Head loss due to friction in pressurized pipe flow
The Hazen-Williams equation estimates friction head loss in full-flowing pressurized pipes using an empirical roughness coefficient C.
Question 3: Which concrete mix property is measured by the slump test?
- Compressive strength
- Water-cement ratio
- Workability (Correct answer)
- Air content
Correct answer: Workability
The slump test measures the workability (consistency) of fresh concrete by recording how much a concrete cone settles after the mold is removed.
Question 4: A two-span continuous beam has a uniformly distributed load. Compared to a simply supported beam of the same span, the maximum positive bending moment in the continuous beam is:
- Larger due to continuity effects
- Equal because load is the same
- Smaller because the interior support reduces midspan moment (Correct answer)
- Zero at midspan
Correct answer: Smaller because the interior support reduces midspan moment
Interior supports in continuous beams create negative moments that reduce positive midspan moments compared to simply supported beams.
Question 5: In soil mechanics, the coefficient of consolidation (Cv) is used to predict:
- Shear strength of sand under dynamic load
- Rate of settlement in saturated clay (Correct answer)
- Bearing capacity of shallow foundations
- Lateral earth pressure on retaining walls
Correct answer: Rate of settlement in saturated clay
Cv governs the rate at which excess pore water pressure dissipates and primary consolidation settlement occurs in saturated fine-grained soils.
Question 6: What does the Thornthwaite method estimate in hydrology?
- Peak flood discharge using rational method
- Potential evapotranspiration based on temperature and latitude (Correct answer)
- Groundwater recharge rates
- Sediment load in rivers
Correct answer: Potential evapotranspiration based on temperature and latitude
The Thornthwaite method estimates potential evapotranspiration using mean monthly temperature and day-length adjustments for latitude.
Question 7: For a steel W-section beam in flexure, the plastic section modulus Z is always __________ the elastic section modulus S.
- Equal to
- Less than
- Greater than (Correct answer)
- Unrelated to
Correct answer: Greater than
The plastic modulus Z accounts for full yielding of the cross-section and is always larger than the elastic modulus S, giving a shape factor greater than 1.
In retaining wall design, what is the primary purpose of a drainage layer or weep holes?