分层开采采空区下大断面切眼支护

针对采空区下大断面切眼掘进围岩变形规律及控制问题,采用FLAC数值模拟对设计支护方案进行分析,并通过工程应用及现场实测验证支护方案的合理性.结果 表明:采用锚网索+金属棚+单体支柱联合支护有效降低顶板位移,以中部单体支柱为界形成一大一小两个下沉区域;支护后应力重新分布,前后表面形成鲜明对比,前表面卸压区分为一大一小半椭圆形,后表面应力分布状态与无支护条件基本一致;支护前后减沉率最大达到38.73％;现场应用监测顶板最大下沉值为12 mm,两帮移近量最大为6 mm.围岩控制效果良好,不仅为后续工作面开采提供参考依据,也为中外类似条件煤炭资源的回收利用提供良好借鉴.

Study on the support of large section off cut under mined-out area in slicing mining

Aiming at the deformation law and control problem of surrounding rock in large cross-section cut driving under mined-out area, FLAC numerical simulation is used to analyze the design support scheme, and the rationality of the support scheme is verified by engineering application and field measurement. The results show that: the combined support of anchor mesh cable, metal shed and single pillar can effectively reduce the roof displacement, and form a large and a small subsidence area with the central single pillar as the boundary; after the support, the stress is redistributed, and the front and rear surfaces are in sharp contrast; the front surface pressure relief is divided into a large and a small semi ellipse, and the stress distribution on the rear surface is basically consistent with the condition without support;The maximum settlement reduction rate before and after support is 38.73%; the maximum subsidence value of the roof is 12mm, and the maximum displacement of two sides is 6mm. The effect of surrounding rock control is good, which not only provides reference for subsequent mining face, but also provides a good reference for the recovery and utilization of coal resources under similar conditions at home and abroad.