基于压密和损伤函数复合作用的单轴压缩本构关系

对西部钙泥质胶结砂岩进行单轴压缩实验。考虑压密阶段和损伤阶段应力应变曲线的变化特点，分别将压密阶段的体积应变和加载过程中的声发射累计数作为表征压密状态和损伤状态的参量，进行归一化后分别用于描述压密和损伤特征，并选取Logistic函数和指数函数进行回归拟合得到加载过程中的压密函数和损伤函数。结合试件的弹性变形特点，对压密函数和损伤函数进行线性组合，分别对由载荷控制和位移控制（包括峰前和全过程）的单轴压缩实验得到的应力应变曲线进行回归分析，得到了砂岩在单轴压缩条件下与实验结果相关性较高的的本构方程，并分析了压密函数和损伤函数中参数的物理意义。

Constitutive Relation of Uniaxial Compression Based on the Pressure Consolidation and Damage Function

The uniaxial experiments of western cemented slime sandstone were conducted. Based on the stress-strain vari-ation at pressure consolidation and the damage stage in the constitutive curve,the volumetric strain in the pressure consolida-tion stage and the acoustic emission in the loading process were considered as the parameters to describe the pressure consoli-dation and damage characteristic. The Logistic function and exponential function were used to fit the curve of volumetric strain and accumulative acoustic emission respectively to obtain the pressure consolidation and damage function. Take a consideration of the elastic deformation characteristic of the sample,the Logistic and exponential function were combined in a liner to make regression analysis on the stress-strain curve obtained by the uniaxial compression tests of loading control and displacement control ( including the before-peak and the whole process) . Then,the well-fitting constitutive equation of sandstone under uni-axial compression was established and the meaning of parameters in the pressure consolidation function and damage function were analyzed.