Experimental Study on Coal Permeability and Damage Evolution Under the Seepage-Stress Coupling

In order to study the damage evolution law of coal under seepage-stress coupling, this paper adopted rock servo triaxial test system conduct permeability for full stress-strain process on 10 sets specimens using steady-state method different confining pressure and osmotic pressure. The results show that has a small fluctuation before stress peak, increases substantially after peak. relationship between plastic variable equivalent strain is proposed. research will provide theoretical basis hydraulic fracturing gas drainage reservoir.