Cantilever Retaining Wall Design

Stability & reinforcement — ACI 318-19 · Rankine / Coulomb · Mononobe–Okabe seismic · SI units (kN, m, MPa)

Input Parameters

kN · m

Geometry

Retained height H ?

Stem thickness t_s ?

Heel length L_h ?

Toe length L_t ?

Footing thickness t_f ?

Toe fill depth h_toe ?

Soil — Backfill

γ_s ?

kN/m³

φ (friction) ?

c (cohesion) ?

kPa

Soil — Foundation

q_a (bearing) ?

kPa

μ (base friction) ?

Passive pressure coefficient K_p

Auto — K_p = (1 + sin φ) / (1 − sin φ) Manual — enter K_p

Range: 2.0 – 5.0

Loads

Surcharge load

q (surcharge) ?

kPa

Seismic load (Mononobe–Okabe)

Input method

Quick — direct k_h input ASCE 7-16 — calculate from S_S & S₁

k_h (seismic coeff.) ?

SDC A/B: 0.05–0.10 · SDC C: 0.10–0.20 · SDC D: 0.20–0.30 · SDC E/F: 0.30–0.40

Site class

S_S (0.2 s) ?

S₁ (1.0 s) ?

Vertical seismic coefficient k_v

k_v = 0 (neglect vertical component) k_v = 0.5 × k_h (ASCE 7-16 §11.8.3)

Materials

Material Properties

f'_c — Concrete [MPa]

MPa

f_y — Rebar [MPa]

MPa

Clear cover ?

Design Criteria

Static

FS_ot (overturning) ?

FS_sl (sliding) ?

Seismic

FS_ot,seis ?

FS_sl,seis ?

Earth pressure method

Rankine — smooth vertical wall, horizontal backfill (conservative) Coulomb — includes wall–soil friction δ (more accurate)

Wall friction angle δ

Auto — δ = 2φ/3 Manual — enter δ

Max ≈ 2φ/3

Wall Cross-Section

Proportional preview — updates with inputs

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Results — Phase 1B

Input panel is complete. Stability checks (overturning, sliding, bearing pressure) and reinforcement design will be added in Phase 1B.