Civil Engineering core subjects
Civil Engineering core in BPSC AE covers structural analysis and design, RCC and steel, geotechnical engineering, hydraulics, transportation, environmental engineering, and surveying. Questions are numerical and code-oriented, so know the governing formula and the assumption behind it.
Core rules and concepts
- Structural analysis: for a simply supported beam with uniformly distributed load w over span L, maximum bending moment = wL²/8 at midspan; maximum shear = wL/2 at supports. For a point load P at midspan, M = PL/4.
- RCC: limit-state design uses partial safety factors; characteristic strength fck and fy are not design strengths. Check deflection, development length, and shear reinforcement.
- Steel: tension members may fail by gross yielding, net-section rupture, or block shear; connections need bolt bearing and shear checks.
- Geotechnical: effective stress σ′ = σ − u; compaction, consolidation, and shear strength are separate phenomena.
- Hydraulics: continuity Q = AV; Bernoulli applies along a streamline for steady, incompressible, frictionless flow.
- Surveying: reduce levels by height of instrument or rise-and-fall; check arithmetic.
Worked example
A simply supported beam of span 6 m carries a UDL of 10 kN/m. Maximum BM = wL²/8 = 10 × 6²/8 = 45 kN·m. Maximum shear = wL/2 = 30 kN. If asked for a point load instead, switch to PL/4; do not mix load cases unless superposition is valid.
Traps
Using wL²/8 for a cantilever is wrong: a cantilever with UDL has wL²/2 at the fixed end. In RCC, do not use characteristic loads as design loads without factors. In soil, total stress minus pore pressure gives effective stress, not the other way round. In surveying, a collimation error affects all readings equally only if the instrument is not adjusted; do not ignore it.