Analytical solution of passive earth pressure

It is well recognised that, when wall friction is present, a non-uniform stress field arises as well as a non-planar failure surface. This renders the problem of computing exact values of earth pressures non-trivial, and analytical solutions are not available in this case. In particular, when dealing with passive earth pressure, current practice relies on solutions provided by limit equilibrium methods with a curved (typically log-spiral) surface, but as these procedures are essentially of kinematical nature they are not conservative. In fact, should the assumed mechanism be admissible in kinematics terms, these solutions represent an upper bound of the exact...