仁遵高速公路小窝凼隧道初期支护稳定性研究

Study on the Initial Support Stability of the Xiaowodang Tunnel on Renhuai-Zunyi Expressway

依托仁遵高速公路小窝凼隧道项目,采用数值模拟软件建立了二维、三维数值模型,分析隧道在整个开挖过程中围岩沉降以及锚杆轴力的变化特征;通过数值计算结果发现:围岩变形呈现初始阶段增长快,之后趋于平缓的单调递增趋势;"支护-围岩"作用体系的演化过程具有时空变化的动态性以及协同作用的整体性、初期支护对围岩压力起到了协调变形与共同支撑的作用以及顶部锚杆与中帮锚杆的变化趋势一致;并经隧道的现场监测验证了数值计算的准确性。通过对小窝凼隧道初期支护稳定性分析,为该隧道的安全施工提供了技术支持。

Based on the project of Xiaowodang Tunnel of Renhuai-Zunyi Expressway,the two-dimensional and threedimensional numerical models are established by using numerical simulation software to analyze the variation characteristics of surrounding rock settlement and bolt axial force during the whole excavation process.The numerical results show that the deformation of surrounding rock increases rapidly at the initial stage,and then tends to be flat and monotonically increasing.The evolution process of the supporting and surrounding rock system is dynamic in time and space,and the synergistic effect is integral.The initial support plays a role of coordinated deformation and common support to the surrounding rock pressure,and the change trend of the top bolt and the middle bolt is consistent.The accuracy of the numerical calculation is verified by the field monitoring of the tunnel.The technical support for the safe construction of the tunnel is provided by analyzing the initial support stability of the Xiaowodang Tunnel.