Civil Engineering Technical Paper: Code-Based Analysis and Design
TNPSC Assistant Engineer (Civil) uses a degree-standard technical paper to test whether you can apply civil engineering theory to field problems. Questions are objective and code-oriented, so a formula is useful only when you know its assumptions, units, and the IS clause behind it.
Core areas and rules
- Structural analysis: distinguish determinate and indeterminate structures; draw SFD and BMD; use slope-deflection, moment distribution, and influence lines for moving loads.
- RCC and steel design: IS 456:2000 limit-state design uses partial safety factors of 1.5 for dead plus live load and material factors of 1.5 for concrete and 1.15 for steel. IS 800:2007 follows limit-state steel design.
- Geotechnical: effective stress is σ′ = σ − u; use Terzaghi bearing capacity and standard Proctor compaction concepts.
- Hydraulics: Bernoulli energy equation, Manning's equation, and discharge measurement by venturi/flume.
- Surveying, transportation, environment: levelling checks, horizontal curves, IRC standards, water demand and treatment units.
Worked example
A simply supported beam of span 6 m carries a UDL of 20 kN/m including self-weight. Maximum bending moment = wl²/8 = 20 × 6² / 8 = 90 kNm; maximum shear = wl/2 = 60 kN. At ultimate limit state, design moment = 1.5 × 90 = 135 kNm. The reasoning is to convert service load to design load before comparing with resistance.
Traps
Mixing kN/m with N/mm²; using total stress where effective stress is required; treating characteristic strength as design strength; ignoring self-weight; and applying a working-stress formula to a limit-state question. Always check the code edition named in the question.