Modifying the Formula of the Ultimate Bearing Capacity of a Shallow Circular Foundation: Fid-Bau Portal

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

Hu, Zhi-ping / Wang, Rui / Xia, Xiang-bo / Wang, Xu / Chen, Yue

The analytical solution for the ultimate bearing capacity of a circular shallow 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 a shallow circular foundation are examined. With the assumption that the global shearing deformation surface of the foundation obeys the sliding surface of Prandtl-Reissner’s classic theory, the destruction soil under the foundation is an indeformable rigid-plastic body, and the failure surface obeys the Mohr-Coulomb yield criterion. Based on the static equilibrium condition of the rigid-plastic body and considering the frictional resistance part $σ$ $\tan φ$ of the failure surface, the theoretical solution for the ultimate bearing capacity of a shallow circular 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 $N_{c}$ , and $N_{q}$ can be increased if the frictional resistance part $σ$ $\tan φ$ of the failure surface is considered, but the variation of bearing capacity coefficient with the internal friction angle of soil are different. Furthermore, the presented theoretical solution, which is a revised calculation method for the ultimate bearing capacity of a shallow circular foundation, is similar to those of Vesic’s semi-empirical equation and other analytic equations.