深部矿井大变形巷道围岩结构控制与效果评价方法研究OA

Taking the transportation roadway of the 5309 working face in a coal mine in the western Jincheng Mining Area as the en-gineering background,this study aims to construct a comprehensive evaluation system for surrounding rock stability and a support optimization method suitable for deep soft rock roadways,and verify their effectiveness through numerical simulation and on-site monitoring.First,the study systematically analyzed the geological conditions and strata pressure behavior characteristics of the road-way surrounding rock,and identified coal stress,roof separation,rib convergence,and drilling cuttings index as the core indicators for evaluating roadway stability.The entropy weight method was used to objectively assign weights to these four indicators,result-ing in weights of 0.15,0.40,0.34,and 0.11,respectively.Based on this,a multi-index comprehensive evaluation model was estab-lished,and a composite support scheme of"full-length anchored high-strength bolts+grouting anchor cables"was proposed as an optimization measure.A three-dimensional roadway model was established using FLAC3D numerical simulation software to com-pare and analyze the surrounding rock displacement field,stress field,and plastic zone distribution before and after support optimiza-tion.The simulation results show that after optimized support,the maximum lateral displacement of the roadway decreased from 0.163 m to 0.132 m,with a reduction rate of 19.02%;the maximum vertical displacement decreased from 0.096 m to 0.073 m,with a reduction rate of 23.96%;roof subsidence decreased by 26.09%,rib convergence decreased by 18.52%,and the plastic zone range was significantly reduced,indicating that the support structure can effectively enhance the overall stability and self-bearing capacity of the surrounding rock.In terms of on-site application,a systematic strata pressure monitoring scheme was formulated,including periodic monitoring of coal stress,roof separation,rib convergence,and drilling cuttings index.Monitoring data show that after sup-port optimization,the maximum roof separation decreased from 35 mm to 26 mm,with a reduction rate of 25.71%;the maximum rib convergence decreased from 185 mm to 96 mm,with a reduction rate of 48.11%;the average drilling cuttings index decreased from 2.2 kg/m to 1.43 kg/m,with a reduction rate of 35%.Calculations using the comprehensive evaluation model based on the entropy weight method show that the roadway stability level was improved from"low"to"high",verifying the effectiveness of the sup-port scheme.