一种解岩土工程变形体-刚体接触问题的有限元法

大多数的岩土工程问题都会涉及到岩土体-结构之间的相互作用，它们之间界面的合理模拟对计算结果有重要的影响。目前常用的Goodman节理单元、Desai薄层单元等虽然简单好用，但也存在着明显的缺陷。相比之下，作为接触问题计算，可更为合理地模拟接触面的力学行为。针对变形体-刚体这种特殊的接触问题，应用变形体的虚功原理建立了相应的虚功方程，在此基础上得出有限元计算公式，并建立了弹塑性接触问题有限元计算的实现方法。通过对刚性条形基础基底压力分布和刚性挡墙土压力分布等算例的计算，验证了该法的正确性和求解工程问题的有效性。

A finite element approach to solve deformable body-rigid bodycontact problems in geotechnical engineering

Almost all the problems of geotechnical engineering have to deal with the interaction between geotechnical media and the structures. Therefore, the simulation of interface plays an important role in the computation. At present, usually the Goodman joint element, Desai thin-layer element etc. are employed to simulate the interface, which is convenient in use but not so reasonable. In contrast, taking as a contact problem, the principal mechanical characters of the interfaces can be reflected as follows: (1) the contact interface is of shear strength which implies that a generic pair of contact points on the interface will displace coincidentally if the tangential force at this point has not reached the limit resistance, else, relative slide between the points will occur along the tangential direction; (2) no matter the relative slide occurs or not, the contact bodies cannot penetrate each other in any wise. A finite element approach to solve deformable body-rigid body contact problems is developed. The finite element formulae are constructed on the basis of the virtual work principle. Also, the techniques to solve the elastoplastic contact problem are given. The examples concerning pressure distribution beneath rigid strip footing and the lateral earth pressure on retaining wall are solved successfully, which verifies the validity of this method.