Considering several sectors that divide the failure zone in which the velocity vector of each sector is the direction at an angle ϕs to the discontinuous rigid boundary, and equating the rate of the external work to the rate of internal energy dissipation, one can obtain a closed form expression for the resultant coefficient of active pressure as Eqs. (1), (2), (3) and (4). By considering soil friction angleϕs, Eqs. (1) and (2) are for non-cohesive soil mass and for a smooth wall (δ