Structural Vertical Depth PE

This is the most common deflection formula on the PE exam. Remember it applies only to uniformly distributed loads on simply supported beams. For other load types or support conditions, use different formulas. The constant 5/384 ≈ 0.01302 is worth memorizing.

This is one of the most fundamental beam formulas. Always verify the beam is simply supported and the load is uniformly distributed. Maximum moment occurs at midspan. Don't confuse with point load formula (PL/4).

Bearing capacity factors (Nc, Nq, Nγ) are always given on the PE exam or can be interpolated from tables. For pure clay (φ=0°), Nγ=0 and the third term drops out. For sand (c=0), the first term drops out. This is Terzaghi's original equation - modern practice uses modified versions with shape factors.

Always verify the section is under-reinforced by checking ρ ≤ 0.75ρb. The formula assumes rectangular stress block and is fundamental to ACI 318. Remember to convert moment units (kip-in to kip-ft) in final answer.

Always check if effective length factor K applies - most real columns are NOT pinned-pinned! Use Le = KL where Le is effective length. Watch for units: keep consistent (all inches or all feet). The equation assumes elastic buckling - check slenderness ratio first.