大倾角煤层旋采巷道围岩破坏机理与支护技术

为解决大倾角煤层旋采巷道围岩变形控制难题,以潘北矿12124大倾角煤层回采巷道为工程背景,采用现场试验、理论分析与数值模拟相结合的方法,研究了旋采巷道破坏规律及上采空区支承压力对巷道的影响,分析得出大倾角煤层旋采巷道围岩破坏机理。结果表明:(1)旋采巷道拐点处断面较大,且受到上采空区及超前支承压力影响,巷道应力值增大,支护体压缩破坏失稳;(2)旋采至拐点前10 m处采空区煤柱应力与采动应力贯通,同时大倾角下巷道受到上覆岩层剪切应力影响,巷道变形增大。通过分析及工程实践,提出并实施了巷道卧底扩刷、锚网索联合支护方式,有效控制巷道变形,取得较好的社会效益。

Roadway Surrounding Rock Failure Mechanism and Support Technology of Revolving Mining Stage in Steeply Inclined

In order to solve the problem of deformation control of surrounding rock in steeply inclined coal seam, this paper takes the mining roadway of 12124 steeply inclined seam in Panbei mine as the engineering background, and uses the method of field test, theoretical analysis and numerical simulation to study the damage law of rotary roadway. The influence of the pressure on the roadway in the goaf was analyzed, and the failure mechanism of the surrounding rock in the steeply inclined roadway was analyzed. The results show that: (1) the cross section of the turning point of the rotary roadway is larger, and the stress value of the roadway increased, and the compression and failure of the support body are unstable due to the influence of the goaf and the advance bearing pressure. (2) The stress and the mining stress of the coal pillar in the goaf at the 10 m of the inflection point are affected, and the roadway is affected by the shear stress of the overburden strata. Through the analysis and engineering practice, the roadway undercover brushing, anchor and cable joint support way are put forward and implemented, and the deformation of the roadway is effectively controlled and the social benefit is achieved.