复杂条件下大采高工作面围岩活动规律分析

Analysis of Surrounding Rock Activity Law of Large Mining Height Working Face under Complex Conditions

为解决6.0 m大采高情况下巷道围岩较破碎、变形破坏严重、底鼓等问题,通过超前支承压力数值模拟、理论分析以及现场实测分析,对418工作面围岩破坏规律进行研究。结果表明:主关键层断裂初次来压步距为83.7 m,周期来压平均步距约为15 m,平均持续步距约为10 m,受采动和顶板岩性的影响,粉砂岩在煤墙内部切断后,加剧细砂岩裂隙发育、破碎、冒落等矿压现象,增加了来压的持续步距为10.3 m;应力峰值42 MPa,位于煤壁前20 m处,影响最大范围185 m,应力集中系数1.67~2.87。

To solve the problems of broken rock,severe deformation and damage,and bottom drum in the case of 6.0 m large mining height,the damage law of surrounding rock of 418 working face was studied by numerical simulation,theoretical analysis and field measurement analysis of the leading bearing pressure.The results show that the initial pressure step of the main key layer is 83.7 m,the average step of the periodic pressure is about 15 m,and the average continuous step is about 10 m.Affected by mining and roof lithology,the siltstone is inside the coal wall.After cutting,the mineral pressure phenomenon such as cracking,crushing and falling of fine sandstone is intensified,and the continuous step of increasing the pressure is 10.3 m;the peak of stress is 42 MPa,which is located 20 m in front of the coal wall,the maximum range is 185 m,and the stress concentration factor is 1.67~2.87.