强夯加固机理的大变形数值分析

强夯过程的动力响应问题非常复杂,理论上难以用解析方法进行分析和求解,目前已有的数值分析方法多为小变形分析方法.考虑到强夯过程中实际土体的变形基本上属于大变形,因此采用大变形几何非线性有限元法分析强夯加固机理.在强夯计算模型中,引入P波阻尼和S波阻尼的概念来说明土体的材料阻尼特性,同时运用改进人工边界法来模拟波在人工边界上的传播.为了保证模型的网格稳定,计算程序中增加了液化单元分析.通过一个工程实例,对其加固深度、变形特征、应力分布进行了数值分析,对比结果验证了强夯大变形分析的正确性

Numerical analysis of dynamic compaction using large deformation theory

The dynamic response analysis of dynamic compaction is very complicated and it is difficult to (adopt) analytic method. Present numerical methods were based on small deformation model, but actually the deformation during dynamic compaction were rather large. So the geometric nonlinear and large deformation finite element method was used to analyze the impact mechanism of dynamic compaction. P wave and S wave were used to clarify the material characteristics of the soil in the model. The finite improved artificial boundary conditions were applied to simulate the waves propagation at the boundary. Liquefaction element method was used in the calculation program for ensuring the mesh stability of the model. An engineering example was studied through the numerical analysis on the improved depth, deformation behavior and stress distribution. Comparative results verified the reliability of the large deformation analysis.