Numerical simulation of effects of different hydraulic cutting arrangement on pressure relief and gas outburst prevention

With the gradual depletion of shallow coal resources,coal mines have entered into the deep exploitation phase.Coal and gas outburst disaster will more and more serious.Using hydraulic cutting technology to coal pressure relief is an effective prevention means of coal and gas outburst.Based on gassy seam in Ping Dingshan coal mine,the effects of different arrangements of hydraulic cutting seam on coal pressure relief and outburst prevention were numerically simulated.The cross direction depth of cutting seam was calculated.The three-dimensional finite element model of hydraulic cutting seam was established.The distribution of X and Y direction stress field were presented based on different cutting arrangements(parallel,diamond,stagger) after cutting.The results show that stress drop induced by the stagger cutting arrangement affects almost the scope of entire coal seam.The magnitude of stress drop in X and Y direction are dramatic reach to 91.6% and 97.8%,which than others two.The stagger arrangement of cutting seam to gas outburst prevention is better which not only can reach the needs of the relief range,but also release stress.