Earth Retaining Structures

Build the pressure diagram by superposing the soil triangle (½K_aγH²), the surcharge rectangle (K_aqH) and the hydrostatic triangle (½γ_wH²), then sum the areas for the total thrust and take moments for its location.

Check the three stability criteria — overturning, sliding and base pressure — with factors of safety of about 1.5–2 before designing the stem, toe and heel as cantilever slabs.

Establish the active and passive pressure diagrams, find the embedment depth from moment equilibrium (about the anchor for anchored walls, about the base for cantilever walls), then locate the maximum bending moment where shear is zero.

Use the apparent (Peck) pressure envelope, not the triangular Rankine diagram, to compute strut loads by tributary area, and check the base against heave in soft clays.

Divide the failure mass into slices, sum the resisting shear (cohesion plus friction on the base of each slice) and divide by the driving component of weight to get FS; the critical surface is the one giving the minimum FS.