含软弱夹层顶板采动巷道冒顶机理与控制方法

Roof fall mechanism and control method of roof with weak interlayer in mining roadway

为揭示采动巷道顶板软弱夹层位态与冒顶的内在关联,以南山矿回采巷道为工程背景,采用理论分析、数值模拟、现场探测等综合研究方法,研究了含软弱夹层顶板采动巷道围岩破裂形态及冒顶机理.结果表明:巷道顶板整体的破裂形态主要取决于软弱夹层厚度、破坏状态及其下位坚硬岩层物理力学性质.采动影响作用下,巷道顶板软弱夹层极易出现破坏,并伴有强烈的膨胀变形压力,有可能致使顶板整体破裂,南山矿回采巷道顶板软弱夹层下位坚硬岩层不足1.0 m时,则出现冒顶隐患.据此,提出了含软弱夹层顶板采动巷道冒顶控制应以抑制软弱夹层破裂区扩展为主,并对南山矿回风顺槽进行了支护设计优化,监测结果表明该支护对策效果良好.

In order to reveal the internal correlation between the weak interlayer position and roof fall of the mining roadway roof,comprehensive research methods including theoretical analysis,numerical simulation and field detection were adopted to study the surrounding rock fracture pattern and roof fall mechanism of mining roadway with weak interlayer roof,which leads to roadway roof fall in Nanshan Coal Mine mining roadway.The results show that the overall fracture shape of the roof of the roadway mainly depends on the thickness of the weak interlayer,the failure state and the physical and mechanical properties of the underlying hard rock layer.Under the influence of mining,the weak interlayer of roadway roof is easy to be damaged,accompanied by strong expansion deformation pressure,which may lead to the whole roof fracture.When the hard rock layer under the weak interlayer in the roof of Nanshan Coal Mine is less than 1.0 m,there will be the hidden danger of roof fall.Based on these results,the roof fall control of the mining roadway with weak interlayer roof is proposed to restrain the expansion of the weak interlayer fracture zone.The support design optimization and effect monitoring of return airway in Nanshan Coal Mine are carried out.The test results show that the support measures can effectively maintain the stability of roadway roof.