基于不同围压下的岩石三轴全过程循环加卸载试验成果曲线,分离出空间塑性主应变;在屈服函数上增加塑性理论中的某种塑性硬化或软化函数项,研究满足Mohr-Coulomb屈服准则的强度参数在初始屈服、峰前硬化及峰后软化全过程中随塑性参量的动态演化规律。通过试验数据整理分析,发现岩石破坏过程中在塑性硬化阶段内摩擦角、剪胀角有一个先增加然后跌落过程,而黏聚力在塑性硬化和软化阶段均减小这一规律;并采用非线性函数对该规律进行拟合回归,得到了内摩角、剪胀角和黏聚力等强度参数以塑性参量为函数变量的演化模型;将该规律应用于拉格朗日数值分析中,模拟了室内大理岩试件破坏过程中的应力应变关系曲线特征。研究表明,基于岩石全过程循环加卸载试验的力学模型能较好描述大理岩的塑性硬化塑性软化的力学行为,具有一定的理论意义和工程应用价值。 Based on the curves of cyclic loading and unloading test under different confining pressures, the space plastic principal strain was separated, and a plastic hardening or softening function term was added to the yield function to study the Mohr-Coulomb yield criterion The dynamic evolution law of plasticity parameter in the initial yield, pre-peak hardening and post-peak softening are all the same. Through the analysis of experimental data, it is found that the friction angle and dilatancy angle of the rock during the process of plastic hardening increase first and then drop, while the cohesion decreases during the plastic hardening and softening stages. Linear regression analysis was performed on the law. The evolution models of internal parameters such as internal friction angle, dilatancy angle and cohesion were obtained with plastic parameters as function variables. The law was applied to Lagrangian numerical analysis to simulate The characteristics of stress-strain curve during the failure of indoor marble specimen. The research shows that the mechanical model based on cyclic loading and unloading test can describe the mechanical behavior of plastic ductility of marble well, which has certain theoretical significance and engineering application value.