Method selection for defining damage variable of rock subjected to static loadings and cyclic impacts

Selecting a suitable physical and mechanics parameter to define damage variable of rock is of great sig - nificance to describe damage cumulative evolution characteristics of rock subjected to coupled static loadings and cyclic impacts. Based on the test results and definition methods of damage variation of rock or concrete under static loads, the parameters of defining damage variable were selected from whether they can reflect the evolution process of rock dynamic fatigue mechanics characteristics and the damage caused by the first impact and the final reasonable damage. The results show that residual strain and wave impedance may be used to define the damage variable of rock subjected to coupled static-cyclic impact loadings. Compared with wave impedance to define damage variable, it seemed that subjective factors have greater effect on residual strain for defining rock damage variable.