软岩应变软化特性的数值解析探讨

Numerical Approach on the Strain Softening Behaviour of Soft Rock

基于实验研究，提出了一种新的考虑时间因素的增量形应力－应变－时间关系，用来描述硅藻软岩的应变软化特性．分别对正常固结和超固结领域软岩试样的应力－应变关系，特别是应变软化特性进行了数值模拟计算，得出了与实验相近的结果．通过对计算结果和实验结果的比较分析，探讨了该计算模型的合理性和可行性，验证了软岩的应变软化特性受应力应变时间依存性的影响．

This paper is concerned with a new concept of modelling the strain softening behaviour of diatomaceous soft rocks based on the laboratory investigation. An approximate solution was described for a stress strain time relation taking account of strain softening phenomenon. The treatment of the post peak behaviour in the calculation is discussed and comparisons of the experimental observations of normally consolidated and overconsolidated specimens with numerically simulated results are given. It is shown that the strain rate effect and strain softening behaviours are controlled by the time dependent stress strain relation.