What it does
Reinforced concrete cantilever retaining wall (stem + heel + toe) design aid. Computes active earth and surcharge pressure, overturning and resisting moments, sliding factor of safety, bearing pressure from eccentricity (full and partial contact), and stem/heel/toe flexure and one-way shear with required-steel and constructible bar-spacing selection. Live stem/footing canvas, pressure and bearing diagrams, per-check pass/fail cards, a symbolic calculation trace, and a structured warning/human-review system.
Engine is benchmarked against the legacy CoLateral retaining-wall spreadsheet and corrects several of its known weaknesses.
What it does not do
Cantilever walls only - gravity, counterfort, segmental, MSE, and basement walls are not implemented. 3 / NBCC style, user verified), not copyrighted code text. Geotechnical parameters (Ka, allowable bearing, friction, passive resistance), drainage/hydrostatic assumptions, governing load cases, and final reinforcement detailing must all be confirmed by the engineer.
Not a stamping engine; every result stays in an engineer-review-required state.
How to use it
Use for preliminary cantilever retaining wall stability and reinforcement screening. Verify all geotechnical inputs, drainage, surcharge treatment, code basis, and detailing before any permit or construction use.
