复杂应力路径下无粘性土的弹塑性数值模拟

A Eiastoplastic Model for Cohesionless Soils under Complex Stress Paths

本文基于标准砂、粉煤灰两种较典型无粘性土的试验研究，建议了一个描述无粘性土复杂应力路径下应力应变特性的弹塑性数值模型。该模型强调塑性应变的大小和方向不仅与当前应力状态有关，而且还决定于当前应力增量的方向。其参数可由简单应力路径的试验确定。为了该模型实际应用，文中还推导了有限元数值计算的弹塑性矩阵。几种典型应力路径的数值模拟结果与有关试验资料比较，表明了该模型的合理性。

Based on the experimental investigation for a standard sand and a coal ash,a elastoplastic model is pre-sented to simulate the stress-strain behaviour of cohesionlea seils under complex stress paths,in which, new fiowlaws and loading-unloading criterla are developed under the following assumption:1.the increment and direction ofplastic strain depend on not only the previous stress history and the current stress state,but also the direction of cur-rent strase increment.2.the stress ratio history is considered as a hardening parameter.It is worthwhile noting thatparameters of the proposed model can be determined conveniently by tests wlth simple stres paths。The validitv ofthis model has been verified through the comparison between predicted results and the experimental dsta under a va-riety of stress peths.