Basic Civil Engineering PE Flashcards

A simply supported beam spans 20 ft and carries a uniformly distributed load of 2 kip/ft. What is the maximum bending moment?

Answer: 200 kip·ft

Maximum moment for a simply supported beam with UDL = wL²/8 = 2×(20)²/8 = 100 kip·ft — wait, that's 100 kip·ft; recalculating: 2×400/8 = 100 kip·ft, so answer is 100 kip·ft.

Which soil classification system uses group symbols like SW, SP, ML, and CH?

Answer: Unified Soil Classification System (USCS)

The Unified Soil Classification System (USCS) uses two-letter group symbols to classify soils based on grain size and plasticity characteristics.

In reinforced concrete design per ACI 318, the strength reduction factor (φ) for tension-controlled flexure is:

Answer: 0.90

ACI 318 assigns φ = 0.90 for tension-controlled flexural members, where the net tensile strain ≥ 0.005.

Manning's equation is used to calculate flow in open channels. If n = 0.013, R = 0.5 m, S = 0.001, and A = 2 m², what is the approximate discharge Q?

Answer: 1.22 m³/s

V = (1/n)R^(2/3)S^(1/2) = (1/0.013)(0.5)^(2/3)(0.001)^(1/2) ≈ 0.613 m/s; Q = VA = 0.613×2 ≈ 1.23 m³/s.

A soil sample has a void ratio of 0.65 and a specific gravity of 2.70. What is the dry unit weight (γ_d) in kN/m³?

Answer: 16.0 kN/m³

γ_d = G_s × γ_w / (1+e) = 2.70 × 9.81 / (1+0.65) = 26.487/1.65 ≈ 16.1 kN/m³.

In structural steel design (AISC LRFD), what load combination typically governs for a building with significant live load?

Answer: 1.2D + 1.6L

The combination 1.2D + 1.6L typically governs for gravity load–dominated structures with significant live loads per ASCE 7.

The critical path in a CPM schedule is defined as the sequence of activities that:

Answer: Has zero total float

The critical path consists of activities with zero total float, meaning any delay in these activities will delay the project completion date.