Application of enhanced assumed strain finite element method to predict collapse loads of undrained geotechnical problems

摘要

Many low-order displacement-based finite elements with exact integration are not suitable for estimating collapse loads of undrained geotechnical problems, especially for axisymmetric cases. As a result, higher-order elements have to be used for these situations. In this technical note, the enhanced assumed strain (EAS) finite element method proposed by Simo and Rifai for elasticity problems are extended to plasticity problems to determine collapse loads. The numerical results for the problem of a smooth rigid surface footing on a deep purely cohesive undrained soil layer are given. It is demonstrated that the four-noded quadrilateral EAS finite element is capable of estimating the collapse loads accurately for both undrained plane strain and axisymmetric problems.