利用非线性弹塑性有限元,对无加筋砂土和采用光滑铜板的加筋砂土平面应变压缩试验结果进行从小变形到破坏的全过程数值解析。考虑到光滑铜板与砂土之间存在滑移,在有限元分析中采用Goodman连接单元作为界面单元。在有限元分析中还需考虑影响砂土变形强度的诸多特性,包括:(1)围压大小的相关性;(2)强度的各向异性;(3)峰值前应变硬化及峰值后应变软化的非线性特性;(4)剪胀性;(5)应变局部化及剪切带形成特性等。结果表明,利用建议的有限元方法得到的加筋砂土平面应变压缩的应变–应力关系与室内试验结果吻合较好,最大应力比和峰值前刚度非常接近试验结果;提出的有限元分析方法可以较准确地捕捉到砂土的剪切带发生、发展状况,合理地模拟加筋砂土的渐进性破坏特性以及加筋材和砂土之间的相互作用机制。
The plane strain compression tests of dense sand reinforced with a smooth brass plate are simulated numerically with a finite element method(FEM). Considering the slippage at the interface between the sand and the reinforcement,Goodman joint elements are used as interface elements in the numerical simulation. In the finite element analysis,the effects of the following factors for sand are also taken into account:(1) correlation of confining pressure;(2) anisotropy of strength;(3) nonlinear characteristics of pre-peak strain-hardening and post-peak strain-softening;(4) dilatancy;and (5) strain localization and forming characteristics of shear zone. The results indicate that the strain-stress relationship obtained by the proposed finite element analysis is generally in good agreement with that of plane strain compression tests. It is found that the maximum stress ratio and pre-peak stiffness in the finite element analysis are quite close to the results of tests. In addition,the results also indicate that the progressive failure of reinforced sand with a development of shear zone can be reasonably examined by the proposed finite element analysis,and the interaction between sand reinforcement at the interface can be well understood.