Civil Engineering
The Civil Engineering domain samples the sub-disciplines a professional engineer is expected to sign off on: structural, geotechnical, water resources, transportation, environmental, and construction/professional practice. Items are applied rather than recall-based - you are given a compact design or field scenario and must identify the governing rule, compute a quantity with correct units, or choose the professionally defensible course of action.
Core rules that carry across sub-disciplines
- Loads: separate service (working) loads, used for deflection, settlement and allowable-stress checks, from factored (ultimate) loads used for strength design. Never mix the two in one equation.
- Units: convert to a consistent set first; kN·m becomes N·mm (×10⁶) whenever you combine with MPa and mm.
- Geotechnical: allowable bearing pressure = ultimate bearing capacity ÷ factor of safety (commonly 2.5–3.0). Footing area is sized on service load plus footing self-weight; settlement is checked separately from bearing failure.
- Water resources: continuity Q = VA; the rational method Q = CiA/360 gives m³/s when i is in mm/h and A in hectares.
- Transportation: design hourly volume comes from AADT through a design-hour factor and directional split - AADT is never the design flow.
- Professional practice: disclose conflicts of interest, seal only work you personally supervised, and report unsafe conditions in writing to the client and authority.
Worked example
A simply supported beam spans 6 m under a factored UDL of 30 kN/m that already includes self-weight. Maximum moment M = wL²/8 = 30 × 6²/8 = 135 kN·m. With d = 550 mm and fy = 500 MPa, take a lever arm of 0.9d and use As = M/(0.87·fy·0.9d) = 135 × 10⁶/(0.87 × 500 × 0.9 × 550) ≈ 627 mm². The 10⁶ factor converts kN·m to N·mm; having done that, check minimum and maximum steel and bar spacing. Note that substituting the service load here would under-reinforce the section.
Traps that cost marks
Ignoring self-weight of beams, footings and retaining walls; using AADT directly as the design traffic; applying ultimate bearing capacity with no factor of safety; reporting a total stress instead of effective stress in a saturated soil; and choosing the "client-friendly" answer in an ethics scenario where disclosure is required.