有空洞地基破坏过程的试验和数值模拟

Experimental and Numerical Test on Progressive Failure Process of Clay Foundation with Cavity Below

首先对该地基的破坏过程进行了室内模型试验,用数码照相记录下了地基的渐进破坏,然后运用所建立的各向异性损伤数值模型,对位移和载荷控制条件下该地基的渐进破坏过程进行了数值模拟试验,重点分析了地基的破坏模式和应力应变关系,并与不考虑拉伸损伤的理想弹塑性模型的计算结果进行了对比。研究发现:有空洞粘土地基首先发生竖向拉伸破坏,然后沿对角连线发生剪切塑性屈服并不断向连线中间扩展,最后在对角连线中间发生拉伸破坏,导致地基发生失稳。数值结果与模型试验结果基本一致,从而为进一步揭示复杂条件下有空洞粘土地基的渐进破坏全过程提供了一种新的数值模拟研究手段。

The progressive failure process of clay foundation with cavity below was firstly recorded by the digital photo technology for indoors model experiment; secondly, an anisotropic damage numerical model, adopting maximal tensile stress as its tension damage criterion and Drucker-Prager criterion as its plastic yield condition, was used to study the progressive failure process of clay foundation with cavity below. The obtained numerical results indicate that the failure of the clay foundation with cavity below is induced by the tensile failure and shearing plastic yield, and corresponding with these of the model experimental. Thus the proposed numerical model provides a new method to further study the failure process of clay foundation with different cavity below.