带垫层桩体复合地基工作性状参数化数值分析

为深化针对复合地基计算理论和设计方法的研究，通过建立带垫层桩体复合地基弹塑性有限元数值模型，采用基于Mohr—Coulomb破坏准则的理想弹塑性本构模型描述地基土的弹塑性本构关系，采用接触对算法描述桩-土界面非连续接触特性，采用无限单元边界模拟半空间地基特征，通过改变垫层刚度、筏板厚度和桩基刚度进行变参数化分析，探讨了复合地基体系中垫层、筏板及桩基三部分对整体受力变形特性的影响，从而更全面和深入地揭示了复合地基体系的工作性能和承载机制，更好地为工程设计与实践提供现实指导与参考。

Parameterized Numerical Analysis on Working Performance of Composite Foundation with Piles and Cushion

In order to intensify the study on design theory together with computation methods of composite foundation, elasto-plastic numerical computation is conducted by developing elasto-plastic FE model in plane stress state, together with adopting Mohr-Coulomb yield criterion to describe the elasto-plasticity of subsoil and Coulomb contact pair theory with penalty algorithm to simulate the discontinuous contact behavior of foundation and soil, as well as using infinite element in modeling boundary. Through the elasto-plastic numerical model of composite foundation with piles and cushion used above, the characteristics of internal forces and deformation of composite foundation system including raft, cushion and piles are analyzed. Furthermore, the respective effect of raft foundation, cushion and piles on the working performance of whole composite foundation system is discussed by changing numerical parameters such as cushion stiffness, raft thickness and piles stiffness. Several conclusion remarks are drawn on the basis of computational results and theoretical analyses, which can provide referable experience to some extent for related engineering practice and design.