Modifying the Formula of the Ultimate Bearing Capacity of a Shallow Square Foundation

Abstract

The analytical solution for the ultimate bearing capacity of a shallow square foundation is studied. The characteristics of existing assumptions, the calculation method, and the yield criterion of the calculation method for the ultimate bearing capacity of the shallow square foundation are examined. The following assumptions are made: (1) the global shearing deformation surface of the foundation follows the sliding surface of Prandtl-Reissner’s classic theory, (2) the destruction soil under the foundation is an indeformable rigid-plastic body, and (3) the failure surface satisfies the Mohr-Coulomb yield criterion. Based on the static equilibrium condition of the rigid-plastic body and considering the limit equilibrium of the passive zone, the theoretical solution for the ultimate bearing capacity of the shallow square foundation is derived and compared with those of Vesic’s semi-empirical equation and other existing analytic equations. Comparison results show that the bearing capacity coefficients