Study on mechanical properties and acoustic emission response of deep granite under hydro-mechanical coupling

Abstract

The study on the mechanical response of deep rock under hydromechanical couplings condition can guide the safe excavation and stability evaluation of deep tunnel engineering. The effects of monotonic loading and cyclic loading on the mechanical properties of granite under 5 MPa pore water pressure and 10 MPa confining pressure were studied by laboratory tests. Before the peak stress, the permeability under monotonic loading was significantly higher than that under cyclic loading, and the permeability under cyclic loading increased sharply after the peak stress. There were two active periods of the acoustic emission energy before peak stress under monotonic loading, but it was always in relative quiet period under cyclic loading before peak stress. Based on the energy theory, the energy evolution of granite was discussed. The dissipation energy can better reflect the effect of loading mode on the energy evolution.