大断面矩形土压平衡式顶管上跨施工对运营地铁隧道变形的影响分析

以川大停车场下穿人民南路地下人行通道矩形顶管隧道工程为依托，采用数值模拟方法对大断面矩形土压平衡式顶管隧道上跨地铁运营区间隧道所引起的地铁隧道变形进行全过程分析研究，并将模拟结果与现场监测数据进行对比，验证模型的合理性。主要结论如下： 1）顶管法隧道上跨施工引发的既有地铁隧道竖向变形受前期掌子面支护压力影响较大，随着开挖面的推进，开挖卸载效应逐渐占据主导地位； 2）地铁隧道横向位移受顶管隧道掌子面支护压力和开挖卸载效应的共同影响，且地铁隧道管片衬砌上半断面的横向位移对掌子面支护压力极为敏感。

Study of Influence of Construction of Large Cross section Rectangular EPB type Pipe Jacking Tunnel on Below Operating Metro Tunnel Deformation

The influence of large cross section rectangular EPB type pipe jacking tunnel under South Renmin Road on below operating metro tunnel deformation is analyzed; and then comparison between simulation results and monitoring data is made to verify the rationality of the simulation model. Some conclusions are drawn as follows: (1) The vertical deformation of the below existing metro tunnel induced by the construction of the pipe jacking tunnel is greatly affected by supporting pressure of excavation face in the early stage; and it is mainly affected by excavation unloading effect as the excavation face moves forward. (2) The horizontal displacement of the metro tunnel is affected by supporting pressure of excavation face and excavation unloading effect; and the upper cross section of metro tunnel segment lining is significantly affected by supporting pressure of excavation face.