Bearing capacity and failure mechanisms of two-tiered reinforced soil retaining walls under footing load

Abstract

The paper presents a numerical modeling study on the bearing capacity of two-tiered reinforced soil retaining walls. Numerical simulations are carried out using the finite element limit analysis (FELA) method, which is validated against results from model tests and other numerical simulation studies. Parametric analyses are carried out to examine the influences that footing location and width, upper wall setback, and reinforcement properties could have on the bearing capacity of two-tiered reinforced soil retaining walls. Results indicate that the variation of bearing capacity with footing distance from the facing is humped-shaped when the footing is located directly above the reinforced zone; the influences of upper wall setback and reinforcement length on bearing capacity diminish with the height of upper wall; and, the bearing capacity of the footing when placed near the wall facing can depend on the ratio of the reinforcement tensile strength values used in the two tiers of the wall. These findings are explained in conjunction with the geometries of slip planes observed in the numerical models.