Study On The Influence Of Gas On Coal Burst Performance

With the increase of mining depth of coal resources in our country,the geological environment of coal is more complex,gas pressure and gas content of the coal seam increase.The purpose of this thesis is to study the influence of gas on the burst performance of coal by means of test determination,theoretical analysis,numerical simulation and field application.To explore the influence of gas pressure on coal seam burst liability,we have invented a kind of coal containing gas burst liability measurement device,the uniaxial compressive strength,the elastic energy index,the impact energy index and the dynamic failure time index of coal samples under different gas pressures were measured,the influence of adsorption gas pressure on energy accumulation and dissipation in coal samples was analyzed,it is found that the burst liability of coal sample decreases with the increase of gas pressure.For the study of mechanical properties of coal containing gas,a gas-solid coupling model is established,the effects of gas pressure on the plastic strain,the stress and energy of coal seam are studied,simulation results show that the existence of gas leads to the transfer of the stress of coal seam and weakens the burst performance of the coal.Based on the influence of gas on the coal burst performance and burst liability,combined with the effect of gas on coal geological factors and mining technology factors.we establish an improved comprehensive index evaluation method,the burst risk assessment of Dafosi mine and Xiaozhuang mine is carried out by using this method.