顶管近距离上跨施工对地铁运营区间影响的数值分析

Numerical Analysis of the Effect of a Pipe Jacking Closely Above an Active Subway Tunnel

随着城市轨道交通的迅猛发展,顶管近距离穿越既有隧道的情况时有发生,尤其在核心城区,在城市交通疏解及工程造价方面,顶管法施工上跨既有区间有着较大的优势。然而顶管施工必然会引起周围的土体的移动对临近的隧道产生影响,因此应控制穿越过程中的地面隆起,还应控制隧道区间的上浮及变形,避免危及行车安全。以苏州某顶管施工穿越1号线地铁区间为背景,采用ABAQUS三维数值模型,对顶管施工过程的隧道区间变形模拟,结合监测数据,对控制区间变形的措施进行探讨,对类似的工程具有借鉴意义。

With the rapid development of urban rail transit,the pipe jacking over the active subway tunnel becomes more and more frequently,especially,within the densely populated urban area with many subway tunnels.Comparing with other construction methods,the pipe jacking method over the active subway tunnel is more cost effective.However,the soil disturbance during the jacking might have an adverse effect on the adjacent tunnel.Both the subsidence and the heave of the ground surface,as well as the＂float＂of the subway tunnel under the pipe jacking area should be well monitored and controlled.This paper presents the three-dimensional numerical analysis results of a pipe jacking installation over Subway Line No.1 in Suzhou City using commercial finite element software ABAQUS.The deformation of the subway tunnel during the jacking operation are simulated and simulation results are compared with field monitoring results.