基于循环加卸载的次加载面模型在岩石中的初步应用

PRELIMINARY APPLICATION OF SUBLOADING SURFACE TO CYCLIC PLASTIC MODEL FOR ROCK UNDER CYCLIC LOADING

为模拟岩体工程在循环荷载作用下的变形特性及相应的稳定性,简要地介绍了次加载面的基本思想。为考虑岩石在三轴压缩状态下和在三轴拉伸状态下不同的强度特性,即应力角效应,在传统的Drucker-Prager屈服准则中引入一种角隅模型,从而形成了修正的Drucker-Prager屈服准则,基于该屈服准则,结合次加载面,提出适用于岩石循环加卸载的次加载面模型。通过参数敏感性分析,发现模型中参数u,C和χ的取值对反映岩石曼辛效应、棘轮效应的影响很大;为验证该模型的适用性和正确性,通过自编程序的数值模拟与岩石模型材料和玄武岩的循环荷载试验结果进行对比,结果表明该模型可以很好地描述岩石的动力变形特性,说明基于循环加卸载的次加载面模型可以运用到岩石中。

To simulate the deformation behavior and the stability of rock mass under cyclic loading,the basic idea of subloading surface was presented. Considering the strength characteristics of rock under triaxial compression and under triaxial tension being different,i.e.,the lode angle effect,a corner model was introduced into the traditional Drucker-Prager yield criterion to form a modified Drucker-Prager yield criterion. Based on the yield criterion,a subloading surface model for the rock under cyclic loading based on the theory of subloading surface was proposed. Through the analysis of parameter sensitivity,it was found that three parameters including u,C and χ of the model had a significant impact on Masing reaction and the ratchet effect of rock. To verify the applicability and validity of the model,a comparison between the simulation and the cyclic loading tests on the model material of rock and basalt was carried out. The results showed that the model described well the dynamic deformation characteristics of rock,indicating that the subloading surface model under cyclic loading was applicable to rock.