煤矿TBM掘进巷道围岩时效变形分析及支护参数优化研究

Time-dependent deformation analysis and support parameter optimization of surrounding rock of TBM tunneling roadway in coal mine

针对煤矿TBM掘进巷道围岩长期稳定性问题,以淮南矿区张集矿TBM掘进某瓦斯抽采巷为工程背景,开展了巷道围岩时效变形分析及支护参数优化研究。通过在TBM掘进巷道施工现场钻取砂质泥岩岩样,开展蠕变试验,获得CVISC蠕变参数;在数值模拟软件中引入CVISC蠕变模型,对不同支护工况下TBM掘进巷道围岩进行为期100d的蠕变变形模拟,获得各支护工况下巷道围岩时效变形特征和应力场及塑性分布区的演化规律;基于数值模拟结果,将优化后的锚杆+钢筋网联合支护体系应用于TBM施工巷道,并对TBM施工巷道进行围岩变形监测和锚杆轴力监测,现场实测结果表明采用的优化支护方案可有效控制围岩变形,且巷道稳定性较好。

In order to maintain the long-term stability of surrounding rock of TBM tunneled coal mine roadway,a gas extraction tunnel in Huainan mining area tunneled by TBM is taken as the engineering background,the time-dependent deformation of tunnel surrounding rock is analyzed and the support parameters is optimized.CVISC creep parameters are obtained by drilling sandy mudstone samples at the construction site of TBM tunnels to carry out creep tests,and the CVISC creep model is introduced into FLAC3D software to simulate the 100-day creep deformation of the surrounding rock of TBM tunnel under various supporting conditions,and the time-dependent deformation characteristics of the surrounding rock and the evolution law of the stress field and the plastic distribution area are obtained.based on the results of the numerical simulation,the optimized bolt+steel mesh support system is applied to the TBM construction roadway,and the surrounding rock deformation and the bolt axial force of the TBM construction roadway are monitored to verify the effect.The field tests show that the optimized support scheme can control the surrounding rock deformation and maintain the roadway stability.