Active earth pressure from c–φ soil backfill

An analytical expression is proposed in this paper for the active earth pressure from c–φ soil backfill on a retaining wall undergoing horizontal translation. It takes into account the arching effects that occur in the backfill. The derived expression is based on the Coulomb failure plane, taking into account wall friction angle, wall adhesion, cohesion, and the internal friction angle of the backfill. It is found to be very important that the active earth pressure coefficient relates not only to the internal friction angle but also to the wall friction angle, the cohesion of soil, the depth below the ground surface and the unit weight of soil, which is consistent with the Richards and Shi solution for static active condition. Special cases of the derived active earth pressure result in the expressions presented by earlier researchers for different field conditions of soil backfill.