土压平衡盾构双孔隧道近接运营隧道施工参数研究

盾构法施工时，为确保土压平衡盾构机下穿施工既有地铁运营隧道的安全，运用三维数值有限元软件，考虑注浆压力和掌子面压力变化的影响，多工况模拟土压平衡隧道施工获得运营隧道变形规律。通过分析土压平衡盾构机下穿施工过程中的位移响应，判定上部交叉运营地铁隧道所受影响。工程实际中对运营隧道的位移进行了监测。根据计算与监测结果，选取在注浆压力0.30~0.36 MPa与土仓压力0.10~0.13 MPa下施工，盾构隧道穿过运营隧道后，运营隧道中股道沉降最大值为0.5 mm，符合规范要求，运营隧道安全。

Study on Construction Parameters of Twin EPB Shield Tunneling Adjacent to Operation Metro Tunnels

To ensure the safety of the earth-pressure-balance(EPB)shield tunnel undercrossing the existing operational metro tunnel in the construction with shield method, the 3D numerical finite element software is used. Considering the influence of the change of grouting pressure and face pressure, the deformation law of the operating tunnel is obtained by simulating the EPB tunnel construction under multiple working conditions. Based on the analysis of the displacement response of the EPB shield tunneling machine in the process of undercrossing construction, the influence of the upper cross operation subway tunnel is determined. In the engineering practice, it is used to monitor the displacement of the operation tunnel. According to the calculations and monitoring results, conclusions are as:using the parameters of grouting pressure 0.30~0.36 MPa and earth pressure 0.10~0.13 MPa, the maximum settlement of the operational tunnel track would be 0.5 mm upon the shield tunnel crossing the operational tunnel, reaching the specification requirement of safety.