Abstract：Obtaining the mechanical parameters of grit stone through a single axis test,using particle flow code(PFC) and fish program to get the meso-mechanical parameters,and carrying compression tests under different confining pressure,the deformation,strength and energy evolution mechanism in deformation and destruction process of grit stone are analyzed.Some main research results are as follows:(1) with the increasing confining pressure,the yield stage of grit stone obviously lengthens,and peak strength increases;(2) after peak strength softening property gradually transits into plastic flow,which shows grit stone brittleness deceases while ductility enhances with the increasing confining pressure,quadratic parabola strength criterion expressed principal stress is more close to the experimental results compared with linear pattern.In the deformation and destruction process of grit stone,energy absorbed mainly transits into the elastic strain energy in elastic stage,and growth rate of elastic strain energy gradually slows while dissipation energy gradually increases in yield stage.Dissipation energy at peak strength is high under high confining pressure,which shows that grit stone interior damage is more serious at high confining pressure.In a post peak strength stage,elastic strain energy sharply decreases under low confining pressure while reduces slowly under high confining pressure.The elastic strain energy limit linearly increases with the incresing confining pressure,and the ratio of elastic strain energy to the total energy rock absorbed decreases at first then becomes a constant.

Keyword：grit stone;strength;energy;evolution mechanism;