二次沿空巷道留巷支护方式及围岩变形规律研究

基于新庄孜矿62110回风巷沿空掘巷后破坏严重出现结构性失稳且后期再需留巷,对二次留巷支护技术进行了研究。分析了巷道破坏原因为地质条件复杂且前期支护参数不合理,结合煤巷预拉力支护理论确定采用＂三高＂锚杆（高强度、高刚度、高预紧力）、锚索补强、深浅孔注浆的联合支护方案。采用快速连续观测法对回采期间巷道的围岩变形进行现场实测,结果表明：高强度架锚注方案可再造围岩结构,减缓顶板活动剧烈程度,工作面后方30～55 m为巷道围岩变形剧烈区,55 m后变形速度趋于稳定。采取该修复方案改善了支护效果,保障了工作面安全回采。

Research on Support Method and Surrounding Rock Deformation Law of Secondary Gateway Retained Along Goaf

Based on the structural stability lost occurred from the serious failure of the gateway retained along the goaf of No.62110 air return gateway in Xinzhuangzi Mine and the gateway reused later,a research was conducted on the support technology of the secondary gateway retained.The analysis showed that the failure causes of the gateway were the complicated geological conditions and the irrational previous support parameters.In combination with the pretension support theory of the seam gateway,the frame/bolt/grouting combined support plan with high strength,high stiffness and high pre-tension bolt,the anchor reinforcement and the shallow borehole grouting was determined.The rapid continued observation method was applied to the site measurement of the surrounding rock deformation in the gateway during the mining period of the coal mining face.The results showed that the high strength frame/bolt/grouting plan could rebuild the surrounding rock structure and could relax the activity serious degree of the roof.The 30~55 m location behind the coal mining face would be the deformation serious scope of the gateway surrounding rock.Beyond the coal mining face 55 m,the deformation speed would be stable.After the repair plan conducted,the support effect was improved and the safety mining of the coal mining face could be ensured.