Civil Engineering Division: Structures, Materials, and Hydraulics
Core concepts to master
The civil syllabus covers structural analysis (determinacy, bending moment and shear force diagrams, trusses, deflection), concrete and steel design (limit state concepts, mix design, reinforcement detailing), soil mechanics (classification, effective stress, bearing capacity, consolidation), fluid mechanics and hydrology (flow measurement, open channel flow, rainfall-runoff), and surveying and transportation basics.
Traps that appear in questions
- Miscounting static indeterminacy: degree = (3m + r) − 3j for a rigid frame, and a hinge reduces the count.
- Confusing total and effective stress in soil: effective stress σ' = σ − u; the water table position changes everything.
- Forgetting that shear force is zero where the bending moment is maximum.
- Using the wrong Manning or Chezy coefficient, or mixing slope units (m/m versus percent).
- Applying working stress factors where limit state partial safety factors are required.
Worked example
A simply supported beam of span 6 m carries a uniformly distributed load of 10 kN/m. Maximum bending moment = wL²/8 = 10 × 36/8 = 45 kN·m at midspan, and maximum shear = wL/2 = 30 kN at the supports. Rule of thumb: for a simply supported beam, Mmax = wL²/8 and the shear diagram is linear, crossing zero at midspan. For soil, a rise in the water table reduces effective stress and therefore reduces bearing capacity - always compute u before σ'.