Three-dimensional passive earth pressures by kinematical approach

The 3D passive earth pressure problem is investigated by the upper-bound method in limit analysis. Three kinematically admissible failure mechanisms referred to as M1, Mn, and Mnt are considered for the calculation schemes. The M1 mechanism is an extension into three dimensions of the classical 2D Coulomb mechanism. The Mn mechanism is a generalization of the M1 mechanism and is composed of a sequence of rigid blocks. Finally, the Mnt mechanism is a more elaborate mechanism in which the final block of the Mn mechanism is truncated by two portions of right circular cones. The lowest upper-bound solutions given by the present analysis are compared with other authors' results and presented in a form of design tables relating the geometrical parameters, soil properties, and the 3D passive earth pressure coefficients.