By the physics-mechanics property examination of rock speimens which are on dry state

natural state and saturation state

Softening property of typical rocks are experimented in Danjiangkou Reservoir area; which can provide basic data for the study on reservoir-induced seismicity mechanism of the subsequent object of Danjiangkou Reservoir. The result shows that values of physical mechanics parameters reduce with the decrease of water ratio in rock

including uniaxial compressive strength

elastic modulus and Poisson's ratio. So the softening coefficients of rocks are directly related to void ratios.