复合加载情况下双层地基极限承载力研究

在复合加载情况下精确求解层状非均质地基的极限承载力，具有很强的工程实用与理论参考价值。基于土体极限平衡理论与通用有限元软件ABAQUS，针对复合加载情况下上硬下软的双层不排水饱和软黏土地基的极限承载力，进行了大量的数值计算，得出了上层土临界深度Hcr的计算公式、竖向极限承载力Pv的计算公式以及复合加载情况下地基破坏时的破坏包络面方程。研究结果表明：上层土临界深度Hcr取决于土层间强度比Su1/Su2；竖向极限承载力Pv与破坏包络面取决于土层间强度比Su1/Su2、上层土深度H1与基础型式。

Study of ultimate bearing capacity of two-layered subsoil under combined loading

To evaluate the ultimate bearing capacity of inhomogeneous subsoil under combined loading is very valuable in engineering practice and significant in theory. Based on limit equilibrium theory of soil, the ultimate bearing capacity of undrained two-layered subsoil under combined loading is achieved by using the general-purpose finite element analysis package ABAQUS. The critical thickness of upper soil Hcr, the ultimate bearing capacity of vertical loading Pv and the failure envelope under combined loading are presented. It is found that the critical thickness of upper soil mainly depends on the undrained shear strength ration of Su1/Su2; the ultimate bearing capacity of undrained two-layered subsoil and the failure envelope under combined loading mainly depends on the thickness of upper soil H1, undrained shear strength ration of Su1/Su2 and shape of foundations.