IMPROVED HARRIS FUNCTION BASED STATISTICAL DAMAGE SOFTENING MODEL FOR ROCKS

In order to reflect the whole process of rock deformation, the Harris function is improved. The micro-unit strength of rock is supposed to obey the improved Harris probability density distribution. The continuum damage theory is combined and the correction of damage variable is considered. As a result, statistical damage softening model of rock is established. The YSJ-01-00 rock triaxial creep testing machine is used to carry out conventional triaxial compression test of red mudstone. Sensitivity of model parameters is analyzed using test data of red mudstone. The physical meanings of the model parameters are described and the expansion process of cumulative damage is analyzed. Test data of monzonitic granite and sandstone in related literatures are used and the test data of three kinds of rock materials are verified using the model of this paper. Constraint range of initial damage coefficient is given. Finally, the rationality and applicability of the model are proved by comparing the experimental curves and theoretical curves of three kinds of rock materials.