NUMERICAL SIMULATION FOR FRACTURE NETWORK EVOLUTION IN COAL-BEARING GAS RESERVOIR RECONSTRUCTION BASED ON DAMAGE THEORY

Based on the characteristics of mechanical response of coal rock under loading, an elastic-brittle damage constitutive relation of coal rock has been proposed, which has been extended to the 3-D stress state, based on the geological strength index. Besides, a numerical calculation method based on the elastic-brittle damage theory has been developed, by analyzing the seepage-stress coupling effect. Then, a computing program for fracture network transformation has been composed to perform numerical simulation of forming process of coal rock under different working conditions, by the APDL language in the ANSYS software platform. The mechanical mechanism of fracture network forming process of coal rock has been