【摘要】 地基承载介质的破坏模式将直接影响到地基承载力计算方法的选择。为了有效地对非均质成层介质的承载力问题进行分析研究,编制了有限元程序对其破坏机制进行模拟计算。结合原位载荷试验,利用试验数据对有限元分析结果进行了验证,表明有限元计算结果是可信的。在此基础上对非均质成层介质地基在外部载荷作用下内部塑性变形和破坏面的形状进行计算分析,结果表明:非均质介质地基的破坏模式主要是整体剪切破坏和局部剪切破坏两种形式;塑性变形首先出现在基础边缘,随着外载荷的增大,塑性变形区域在非均质介质中逐渐扩展并最终形成一个贯通的塑性区。更多还原

【Abstract】 In general,the determination of the failure mechanism for the inhomogeneous subsoil plays an important role in predicting the ultimate bearing capacity. Basing on Duncan-Chang model,a finite element program is compiled to search for the failure mechanism of the inhomogeneous subsoil. Some in-situ loading tests are performed in Tianjin New Harbor area and the experimental data are compared with the computational results from the finite element methods. The reliability of the finite element program is verified through the comparison. By virtue of numerical analyses,the failure process can be reproduced,and the plastic deformation zone and the most-probable rupture surface in the inhomogeneous subsoil are found. It has been found that under the ultimate load the inhomogeneous subsoil exhibits the characteristics of general shear failure or local shear failure. The plastic strains firstly appear on the edge of the footings. With increasing of the load,the plastic zone expands and joints together at last. The appearing of the continuous plastic zone means that bearing capacity failure occurs in the subsoil,and the bearing capacity of the foundation has reached to its ultimate value.更多还原