弹塑性平面应变固结问题的解耦分析

Decoupling analysis of elastoplastic plane strain consolidation

针对弹塑性平面应变固结问题提出了解耦的计算方法,基于数值建模方法建立了多路径的土的弹塑性本构模型,该模型能考虑塑性剪应变vpε与体应变-pε交叉作用及应力路径的影响.将该模型引入弹塑性固结问题中,建立了相应的扩散方程.讨论了此类液-固耦合问题的解耦条件及对应的应力路径.推导了平面应变扩散方程的基本解,该基本解与固体域控制方程构成了半数值半解析求解体系,编制了有限元程序,计算了一个典型平面应变固结沉降算例.对比分析表明该方法能有效地简化计算,能较好反映应力路径对固结的影响.

A decoupled method for elastoplastic consolidation was presented. The elastoplastic models under different stress paths were constructed based on numerical modeling method, which reflected the interaction between εv^p and -↑ε^p and the influence of stress paths. Then, the models were applied to elastoplastic consolidation and the diffusion equation was established. The decoupled conditions of stress paths for the liquid-solid coupling equations were discussed. The fundamental solution for the plane strain diffusion equation was derived. By use of the fundamental solution combined with the control equations of soil filed, a semi-analytical and semi-numerical method was put forward. Moreover, the method was applied to numerical analysis of a plane strain consolidation example. The.result shows that consolidation analysis can be simplified by the method accurately, which can reflect the effect of stress paths.