深井厚煤层大巷孤立煤体冲击危险性评价研究

Study on impact risk assessment of isolated coal mass in roadway of thick coal seam in deep mine

为了探究大采深条件下厚煤层大巷孤立煤体频繁发生冲击地压的原因,以梁宝寺煤矿35000采区为工程背景,采取现场实践、数值模拟等方法分析不同采深、煤厚、大巷间距等因素对大巷孤立煤体冲击地压的影响,提出深井厚煤层大巷孤立煤体冲击地压的危险性评价方法。研究结果表明:大巷孤立煤体的采深与垂直应力峰值呈正相关,采深1200 m时煤体的垂直应力峰值是采深500 m时的3倍左右;大巷孤立煤体随着煤层厚度的增加,其应力集中程度不断升高,且应力峰值向煤体弹性承载区转移;大巷间距越小,孤立煤体弹性承载区应力越集中,发生冲击地压可能性越高;包含开采影响因素和煤层冲击倾向性的大巷孤立煤体冲击危险性评价方法符合现场实际情况,可为大巷孤立煤体冲击危险性评价提供1种思路。

In order to investigate the causes of frequent rock burst in the isolated coal mass in the roadway of thick coal seam under large mining depth condition,taking the 35000 mining area of Liangbaosi coal mine as the engineering background,the influence of different mining depths,coal thicknesses and roadway spacing on the rock burst of isolated coal mass in roadway was analyzed by using the methods of field practice and numerical simulation,and a risk evaluation method of rock burst in the roadway of thick coal seam in deep mine was proposed.The results showed that the mining depth of isolated coal mass was positively correlated with the peak vertical stress,and the peak vertical stress of coal mass at 1200 m mining depth was about 3 times of that at 500 m mining depth.With the increase of coal seam thickness,the stress concentration degree of isolated coal mass in roadway increased continuously,and the peak stress transferred to the elastic bearing area of coal mass.The smaller the roadway spacing,the more concentrated the stress in the elastic bearing area of isolated coal mass,and the higher the possibility of rock burst.The method of roadway rock burst risk including the mining influencing factors and coal seam burst tendency was in line with the actual situation in the field,which provides an idea for the risk assessment of coal seam roadway burst.