针对高煤帮巷道两帮的大变形问题,以霍尔辛赫煤层条件为例,数值模拟分析了其煤帮破坏机理,即在围岩压力下产生压剪破坏,四角形成强剪切区,连接成似“C”形剪切带,上部煤体斜向滑移,在巷帮中部变形最大;采用锚杆锚索联合支护后,剪切应变值及塑性破坏范围均有所减小。根据模拟结果及相关成功工程经验,提出煤帮层次化支护技术,即锚索或注浆锚索配合锚杆支护。在西辅运大巷进行了强力锚杆锚索控制高煤帮的现场试验,监测表明巷帮锚索有效控制了帮部顶角剪切滑移造成的失稳,巷道变形和离层均较小,取得较好支护效果。
Aiming at the large deformation of high coal ribs, the failure mechanism of coal ribs was analyzed with numerical simulation based on the coal seam conditions in Huoerxinhe Coal Mine. Compression-shear failure happened under surrounding rock pressure, forming strong shearing zone in four comers and "C" shearing belt in sides. The upper coal slipped and largest deformation appeared in the middle part of both ribs. Shear strain and plastic zone were both decreased after combined support of bolt and cable. According to modeling results and successful project experiences, hierarchical support was proposed, using cable and grouting-cable to cooperate with bolt. Site experiment was carried out in west auxiliary transportation roadway. Monitoring data showed that ribs cables controlled the shearing slip of top sides; supporting effect was favorable with small deformation and roof separation.