不同水力割缝布置方式对卸压防突效果影响数值模拟

随着浅部煤炭资源逐渐枯竭,我国煤矿相继进入深部开采阶段,煤与瓦斯突出灾害愈趋严重,采用水力割缝技术对煤体卸压是煤与瓦斯突出防治的一种有效手段。以平顶山某煤矿深部突出煤层为例,进行了不同水力割缝布置方式对煤层卸压防突效果影响的数值模拟研究。计算了水力割缝切割煤体横向深度,建立了水力割缝三维有限元模型,数值模拟得到了三种水力割缝布置方式（平行、菱形、交错）对煤体X、Y向应力场影响变化规律。结果表明：交错排列的水力割缝布置方式导致应力降影响范围几乎覆盖整个煤层,X向、Y向应力降显著,应力降幅度分别为91.6%、97.8%,均大于其他两种布置方式。因此交错排列的水力割缝布置方式既可以满足卸压范围需要,同时也能够较好释放深部煤层应力,卸压防突效果较好。

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 arrangementsof 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.