考虑围压影响的岩石峰后应变软化力学模型

试验表明,随着围压增加,岩石峰后残余强度和割线模量增加,如何模拟围压对岩石峰后应变软化力学行为的影响是岩石峰后力学行为研究的关键。利用Z.Fang1]提出的峰后强度下降指数描述围压对岩石峰后残余强度和割线模量的影响,与摩尔-库仑模型结合,建立了考虑围压影响的岩石峰后应变软化力学模型。在FLAC环境下,利用Fish函数方法开发了相应的数值计算程序。数值算例研究了Tennessee大理岩在不同围压下的应变软化过程,模拟结果与试验数据基本一致,表明建立的模型合理,可以应用于岩石峰后软化过程的模拟。

Post-peak strain softening mechanical model of rock considering confining pressure effect

It has been proved by tests that post-peak strength of rock enhances with the increment of confining pressure. How to model the effect of confining pressure on strain softening of post-peak strength rock is a key issue. The degradation index of post-peak strength presented by FANG Z1] is presented to model the effect of confining pressure on the post-peak strength and the secant modulus of rock. In combination with Mohr–Coulomb model, the strain softening model of rock with confining pressure is presented. Fish function method within FLAC is used to perform the model. In case study, the strain softening processes under variable confining pressures for Tennessee marble are modeled. The results show that the modeling results accord with experimental data; and the model presented is effective method to model the strain softening processes of post-peak strength rock.