针对大梁隧道工程地质特点,开展隧洞开挖后围岩大变形现场监测与分析,得知隧洞变形具有变形速度快、持续时间长和变形量大的特点,最大下沉量可达55 cm,最大变形速率为1.69 cm/d。通过开展岩石试样单轴、三轴压缩破坏试验,采用广义Hoek-Brown准则,确定岩体常规弹塑性力学参数;结合隧洞变形监测数据,将隧洞围岩视为具有弹塑性流变行为的连续介质,采用经验流变模型,开展有限元反演分析,得到岩体流变力学参数。根据数值仿真结果,分析隧道围岩位移、应力及损伤区分布规律,从而为支护方案修改设计和参数调整提供依据。在上述研究基础上,应用新奥法施工力学原理,提出加大预留变形量,拱顶超前注浆加固围岩,打拱脚长锚杆控制拱架整体下沉,并采用钢拱架(拱架之间采用型钢连接)+锚杆+钢筋网协同支护,构成软岩大变形洞段联合支护方案,成功解决了大梁隧道破碎、软弱围岩地段的施工与支护难题,经施工后巷道稳定性良好。 According to the geological characteristics of the girder tunnel engineering, on-site monitoring and analysis of large deformation of surrounding rock after tunnel excavation shows that tunnel deformation has the characteristics of fast deformation, long duration and large deformation, the maximum sinkage can reach 55 cm, the maximum The deformation rate is 1.69 cm / d. Through the uniaxial and triaxial compression failure tests of rock samples, the generalized Hoek-Brown criterion is used to determine the conventional elasto-plastic mechanical parameters of rock mass. Based on the data of tunnel deformation monitoring, the surrounding rock of the tunnel is regarded as continuous with elasto-plastic rheological behavior Medium, using empirical rheological model, carry out the finite element inversion analysis, rheological mechanical parameters of rock mass. According to the numerical simulation results, the displacement, stress and the distribution of damage zone of surrounding rock are analyzed, which provides the basis for the modification design and parameter adjustment of the support scheme. On the basis of the above research, applying the new Austrian law of construction mechanics, it is proposed to increase the amount of standing deformation, to reinforce the surrounding rock by advanced vault grouting, and to control the overall settlement of the arched arch by arched long legs. The steel arch between the arch frame) + bolt + steel mesh synergistic support, constitute soft rock large deformation section of the joint support program successfully solved the beam tunnel broken, weak surrounding rock sections of the construction and support problems, after construction After the roadway stability is good.