极弱胶结地层开拓巷道围岩演化规律与监测分析

Evolution of surrounding rock in pioneering roadway with very weakly cemented strata through monitoring and analysising

针对极弱胶结地层的复杂地质条件,基于岩石力学基本试验及巷道围岩松动圈测试,揭示了极弱胶结地层巷道围岩力学及变形破坏特征;采用FLAC3D模拟研究了5种巷道开挖后的巷道围岩变形特征及围岩塑性区演化规律,分析了不同埋深和侧压力系数对巷道围岩稳定的影响规律;及时掌握了极弱胶结地层巷道围岩的变形与支护结构受力情况,优化巷道支护设计与指导施工,对巷道围岩收敛变形、工字钢支架受力及混凝土衬砌受力等进行了实时监控量测,监测结果表明,在极弱胶结地层开拓巷道采用工字钢、钢筋网+混凝土衬砌的联合支护方式,有效地控制了巷道围岩的变形和保证了巷道的长期稳定及安全。

Based on the tests of rock mechanics and the measurement results of relaxation zone of roadway, the characteristics of deformation and failure of the surrounding rock masses were revealed under conditions of very weak cementation formation of complex geology. With FLAC3D, the variation law of deformation and plastic zone of surrounding rock was studied after excavation in 5 kinds of roadway, the effective laws of the depths and lateral pressure coefficient on the stability of the surrounding rock were researched. To master the deformation of surrounding rock and mechanical properties of the support structure timely, optimize the design of roadway supporting and guide the construction, the convergence deformation of the surrounding rock, mechanical properties of the I-beam and the concrete lining were mo- nitored at real-time. The monitoring results show that, by using the combined support of I-beam, mesh reinforcement and concrete lining in a development roadway of poorly consolidated formations can effectively control the deformation of the surrounding rock and ensure stability and safety of the roadway in long time.