堤基管涌侵蚀破坏过程的无单元法模拟

针对堤基管涌侵蚀破坏过程的复杂渗流场模拟问题，采用无单元Galerkin法数值模拟研究管涌动态发展过程及机理，介绍了管涌区域破坏的判别方法、管涌尖端附近节点加密方法等，并结合砂槽模型试验和有限元模拟结果对无单元法的计算结果进行了验证与分析。结果表明，采用无单元法计算得到的管涌渗流场和有限元计算结果基本吻合，且管涌发展过程和模型试验结论较为一致；获得了管涌侵蚀破坏过程中管涌通道尖端水平渗透比降的变化规律，弥补了砂槽模型试验的不足。

Simulation of Piping Erosion Process of Dike Foundation with Element Free Method

Aiming at the simulation of complicated seepage field of piping erosion failure in dike foundation, element free Galerkin method (EFGM) is adopted to study the dynamic development and mechanism. Failure criterion for piping zones and approach of nodes refinement around piping tips are introduced specifically. Meanwhile, EFGM results are verified and analyzed based on the results from flume model test combined with those from finite element simulation. The results show that the seepage distribution obtained by EFGM accords with that of finite element; the development process of piping is consistent with the conclusion of flume model test; moreover, variation rules of the horizontal seepage gradient at the tip of piping channel are obtained, which remedies a defect of flume model test.