泥岩顶板大断面开切眼支护技术优化实践

Optimization practice of support technology for large section open-off cut with mudstone roof

为减少城郊煤矿二2煤层开切眼围岩的变形,保证设备的正常安装,开展了原切巷支护方案的优化研究。研究表明,二2煤层及直接顶板强度低以及开切眼的跨度大、部分区域顶板淋水是造成支护效果不理想的主要原因。采用FLAC3D数值模拟对不同支护方案下的巷道塑性区深度进行了定性分析,确定了锚索长度为10 m,顶锚杆数量为10根/排,长度为2500 mm。现场应用表明,采用优化后的支护方案,巷道变形时间短,最大顶板下沉为43 mm,两帮移近量为21 mm。

In order to reduce the deformation of surrounding rock in the open-off cut of No.22 coal seam in Chengjiao Mine and ensure the normal installation of equipment,the optimization research of the original cutting roadway support scheme was carried out.The research showed that the main reasons for the unsatisfactory support effect were the low strength of No.2 coal seam and the direct roof,the large span of the open-off cut and the roof water spray in some areas.FLAC 3D numerical simulation was used to qualitatively analyze the plastic zone depth of roadway under different support schemes.The length of anchor cable was determined to be 10 m,the number of top bolts was 10/row,and the length was 2500 mm.The field application showed that after adopting the optimized support scheme,the deformation time of the roadway was short,the maximum roof subsidence was 43 mm,and the displacement of the two sides was 21 mm.