巨厚砾岩下特厚煤层巷道掘进冲击地压防治研究

Study on Prevention and Control of Rock Burst During Roadway Driving in Extra-thick Coal Seam Under Huge Conglomerate

以河南某矿23150工作面为工程背景,采用现场实测、理论分析、数值模拟等方法,研究了巨厚砾岩下特厚煤层巷道掘进异常的机理以及开采局部保护层的防治方法。得出以下结论:采空区上覆岩层处于非充分采动状态,巨厚砾岩尚未破断,自重应力与巨厚砾岩传递应力叠加形成了下平巷的高应力场,高应力是特厚煤层巷道冲击危险的主要原因;合理的局部保护层开采范围是保证巨厚砾岩下特厚煤层巷道处于低应力状态的关键。通过建立局部保护层宽度计算的力学模型,推导了局部保护层开采范围,并通过数值模拟验证了理论计算的正确性。

Taking the 23150 working face of a coal mine in Henan as the engineering background,the mechanism of abnormal roadway driving in extra-thick coal seam under huge conglomerate,as well as the prevention and control methods of mining local protective layer were studied by means of field measurement,theoretical analysis and numerical simulation.The following conclusions were obtained.Firstly,the overburden strata of goaf were in the state of insufficient mining,the extra-thick conglomerate had not been broken,the high stress field of the lower level roadway was formed by the coupling superposition of the gravity stress and the transmission stress of the extra-thick conglomerate,and the high stress was the main reason for the roadway impact risk.Secondly,the reasonable mining range of the local protective layer was the key to ensure that the roadway was in a low stress state.By establishing a mechanical model for calculating the width of the local protective layer,the mining range of the local protective layer was deduced,and the correctness of the theoretical calculation was verified by numerical simulation.