🧱 Retaining Wall Stability

Cross-section — adjust controls to test stability

Stability results

Kₐ = tan²(45°−φ/2)—

Active thrust Pₐ—

Wall weight W—

FS overturning ——

FS sliding ——

Eccentricity e (B/6=—) ——

Max base pressure—

Rankine active pressure. The retained soil pushes with coefficient Kₐ = tan²(45°−φ/2). Pressure grows linearly with depth: σₐ = Kₐ·γ·z, plus Kₐ·q from the surcharge. The total thrust Pₐ = ½·Kₐ·γ·H² (+ Kₐ·q·H) acts at H/3 from the base and tries to tip and slide the wall. The wall resists by its weight: overturning needs FS = M_resist/M_overturn ≥ 2.0, sliding needs FS = μ·W/P_h ≥ 1.5, and the resultant must stay within the middle third (e ≤ B/6) so the base never lifts in tension.