某隧道围岩参数反演分析及实时施工应用

以某隧道监测到的隧道围岩位移变形数据为依据,选取围岩岩体的弹性模量E与初始地应力侧压力系数K作为反演参数,采用黄金分割法和FLAC3D数值模拟对隧道洞口浅埋段及洞身段围岩进行位移反分析优化计算。在此基础上将反分析得到的围岩力学参数应用于掌子面前方围岩变形的数值模拟计算,将其结果与隧道施工中监控量测结果进行对比,验证了位移反分析在隧道施工中实时应用的可行性,并将拱顶沉降量的预测结果用于设定围岩开挖的预留变形量,通过控制超挖量,减少喷射混凝土用量,节约工程成本。

Back Analysis and Real-time Construction Application of Tunnel Surrounding Rock Parameters

Based on the displacement deformation monitoring data of a certain tunnel surrounding rock, the surrounding rock elastic modulus E and the initial stress of lateral pressure coefficient K were selected as inversion parameters. And then the displacement back analysis optimization calculation were implemented on the shallow buried portal and central of tunnel surrounding rock with the golden section method and FLAC3D numerical simulation. The rock mechanical parameters obtained by back analysis were applied to the numerical simulation of deformation of the surrounding rock which located in front of the tunnel face. The results were compared to the real-time monitoring results in tunnel construction. The feasibility of displacement back analysis in the real-time construction was verified. Meanwhile, the predicted results of vault settlement was used to set rock excavation deformation allowance. The quantity of shotcrete was reduced by controlling the over break volume, and the project cost was also saved.