浅埋高强度采场回撤阶段围岩破断机理及控制

Mechanism and Control of Surrounding Rock Breakdown at Mining Equipment Withdrawn Stage from High Intensity Coal Mining Face in Shallow Depth Seam

针对神东矿区浅埋高强度开采工作面回撤过程中支架压死频繁发生的现象,采用理论和数值分析手段,对回撤阶段支架压死现象发生的机理进行了研究。结果表明:回撤巷道同老顶断裂线处于合理的时空位置关系是工作面实现低压力回撤的关键;解释了荷载传递具有时效性的原因,工作面长时间停滞导致老顶和荷载层破坏出现宏观滑移面后其荷载有足够的时间传递至工作面支架之上,使其由"给定变形"转变为"给定荷载"工作状态是造成回撤过程中工作面支架压死的主要原因;根据预测的老顶断裂线所处区域的不同,提出了改变采高、工作面推进速度、局部充填的顶板控制措施,并应用于乌兰木伦煤矿,实现了工作面的安全、快速回撤。

According to a powered support jammed phenomenon frequently occurred in a mining equipment withdrawn process from high intensity coal mining face in a shallow depth seam of Shendong Mining Area, a theoretical and numerical analysis was applied to the study on the mechanism of the powered support jammed phenomenon occurred at the equipment withdrawn stage. The results showed that the withdrawn gateway and the main roof breaking line being in a rational time and space location relationship would be a key of the coal mining face to realize a withdrawn under a low roof pressure. The causes of the time effect from the load transmission were explained and a long time standstill of the coal mining face would cause failures of the main roof and loading stratum. When a macro sliding surface occurred, the roof load would have a sufficient time to be transited on the top of the powered support applied in the coal mining face and thus a working status changed from ＂a given deformation＂ to ＂a given load＂ would be the main cause to cause the powered support jammed occurred in the withdrawn process. According to the predicted main roof breaking line in different area, a changed mining height, pushing forward speed of the coal mining face and local backfill roof control measures were provided and applied to Wulanmuluen Mine. A safe and rapid equipment withdrawn operation of the coal mining face was realized.