近距离特厚煤层受上层煤柱影响下的掘巷矿压显现机理及防治技术研究

Strata Behavior Mechanism and Prevention Technology of Roadway Driving under the Influence of Upper Coal Pillars in Close Extra-thick Coal Seam

针对上覆遗留煤柱集中应力影响下,巷道掘进困难,矿压显现严重等一系列问题,本文以塔山煤矿30501首采工作面掘进巷道为研究对象,采用理论分析和现场实践相结合的方法,对巷道掘进过程中异常矿压显现影响因素及防治措施进行研究。结果表明:遗留煤柱引起的工作面顺槽围岩高集中应力是异常矿压发生的基本条件,胶带巷距遗留煤柱水平距离太近是导致矿压显现的直接原因,2#煤层开采后上覆坚硬顶板未破断产生的弹性能是导致遗留煤柱上应力集中的主要原因。通过现场实践证明,采用包括巷道合理优化布置、对上覆遗留煤柱水力致裂及加强支护措施等方法是合理的,通过巷道掘进期间巷道变形监测,验证了以上防治技术的有效性。研究结果可为相似开采条件下的其他矿井及工作面提供借鉴。

Under the influence of the stress concentration of overlying residual coal pillars,a series of problems have occurred,including difficult roadway driving and severe mining pressure.This paper takes the roadway driving in the 30501 first mining face of Tashan Mine as the research object,and combines the theoretical analysis and field practice to study the factors and preventive measures of abnormal ground pressure during the driving process.The results show that the high concentrated stress of the surrounding rock at the working face along the gateway caused by residual coal pillars is the basic condition for the occurrence of the abnormal mine pressure;the close horizontal distance between the belt roadway and residual coal pillars is the direct cause of the mine pressure;after mining the No.2 coal seam,the elastic energy produced by the unbroken overlying hard roof is the main cause of stress concentration on the residual coal pillars.The field practice has proved it reasonable to adopt the methods,including reasonable and optimized roadway layout,hydraulic fracturing of overlying coal pillars,and strengthened supporting measures.By monitoring the roadway deformation,the effectiveness of the above prevention technology is verified.The research could provide reference for other mines and working faces under similar mining conditions.