Study On The Failure Rules Of Gaseous Coal And Rock

In this paper, starting with meso-damage mechanics, penetration mechanics of seam gas and rock mechanics, a flow-stress-damage coupling model is built, which has some guidance significance to explain stability problem during rock progressive failure under gas seepage from the point of micromechanics and provides a possible way to promote coal dynamic stability under complicated gas seepage effect.After the gas occurrence characteristics in coal and the adsorption theory are analyzed and the main physical parameters are given, the gas unidirectional flow liquid-solid coupling equation and the deformation field equation of coal rock are built. Coal-rock failure mode and strength criterion is determined according to mechanical properties of materials microscopic primitives, and because the permeability will change in process of coal damage evolution, coal permeability coefficient-stress effect equations are given. Then a flow-stress-damage coupling model in failure process of gaseous coal and rock is built, and which is solved using finite-difference method. At last, the computer program is edited according to the solution, which is used to calculate gassy coal-rock deformation and failure process, gassy coal-rock creep injury and failure process and gassy coal-rock permeability evolution under the displacement loading control method. And the gassy coal failure laws under different loading condition and the penetrability change laws were obtained by actual example calculation. At last, the correctness of coupled solid-gas flow model in failure process of gaseous coal is verified by the simulation results of RFPA2D-Flow.