软岩巷道围岩稳定性分析及锚固优化设计研究

Study on Stability Analysis and Anchorage Optimization Design of Surrounding Rock in Soft Rock Roadway

通过对嘉禾矿浦溪井2152底板巷围岩变形严重的支护问题进行分析,得出围岩所处泥质砂岩岩层属于软岩序列以及高偏应力引起围岩出现不规则塑性区是锚杆出现整体拔出失效的主要原因。根据蝶形塑性区破坏理论,提出“让抗结合、局部加强支护、全断面协调变形”的支护思路,对2152底板巷支护方案进行了优化,采用“锚杆、钢筋网、喷浆、预应力锚索”的联合支护方式。通过FLAC^(3D)有限元方法对优化支护方案进行了模拟研究并在井下进行了试验,现场试验表明:围岩顶底板移近量在125 mm左右,两帮移近量在140 mm左右,优化的支护方案有效地控制了围岩的变形量,围岩稳定性得到提高。

Through the analysis of the serious deformation of surrounding rock of the 2152 floor roadway of Puxi well in Jiahe mine,it is concluded the overall pull-out failureis caused by surrounding rock composed of argillaceous sandstone belonging to the soft rock and the irregular plastic zone of the surrounding rock.According to butterfly-failure theory of mining roadways,the support idea of"combining resistance with resistance,strengthening support locally,and coordinating deformation of the whole section"is proposed.The support scheme of 2152 roadway is optimized,and the comprehensive support mode of"anchor bolt,reinforcing mesh,shotcrete,and prestressed anchor cable"is adopted.The optimized support scheme was simulated by FLAC^(3D) finite element method and tested underground.The field test shows that the roof and floor displacement is about 125 mm,and the two ribs displacement is about 140 mm.The optimized support scheme effectively controls the deformation of surrounding rock,and the stability of surrounding rock is improved.