厚泥岩复合顶板煤巷围岩控制技术研究

 针对首山一矿11061工作面运输平巷厚泥岩复合顶板强度低、无稳定承载结构、顶板下沉量大的问题，通过监测巷道围岩破坏及离层发育，统计巷道破坏具体形式，分析得出复杂应力条件下厚泥岩复合顶板巷道破坏的力学机制。基于普氏拱理论，结合现场具体支护和破坏状况，提出“预应力锚杆+锚索承载结构，配合原生裂隙区域注浆加固”的改进支护方案：预应力锚索(杆)形成的主、次承载结构协同作用，在两承载层间的泥岩顶板形成压缩区限制离层发展；布置倾斜锚索与垂直锚索，限制巷道顶帮角处围岩塑性区扩展，防止锚索锚固点所在岩层破断失去承载能力。依据塑性圈理论和数值模拟等手段，确定锚杆、锚索等具体支护参数，利用分区注浆加固泥岩强烈膨胀与松动破坏区域。数值模拟和现场工程实践的结果表明：与原支护方案对比，改进的支护方案巷道变形量减少约50%，巷道围岩完整程度明显提高，有效地控制了厚泥岩复合顶板变形与破坏。

Research on surrounding rock control of coal roadway with thick mudstone compound roof

The headgate of 11061 longwall face in Shoushan No.1 coal mine had the problems of low strength of thick mudstone compound roof, unstable bearing structure and the big deformation of roof. By monitoring on propagation of failure and separation of surrounding rock and counting failure model of the headgate，the failure mechanism of roadway with thick mudstone compound roof and complex stress distribution were gotten. Based on the compressive arch theory and in-site supporting and failure condition, an improved supporting method which is pre-stressed bolts and cables as the main bearing structure combined with grouting reinforcement in fissile zone was proposed. Pre-stressed cables and bolts built the primary and secondary bear structure. The separation of compound roof seam would be limited and the plastic range developing around the roof corner would be decreased. The detail parameters of cables and bolts were decided by the plastic ring theory and numerical method. The comparing results between the improved supporting method and former supporting method showed that: the deformation decreased 50% in the improved supporting method, the stability of the headgate?s surrounding rock enhanced obviously and the large deformation and failure in thick mudstone compound roof were well controlled.