深基坑施工对既有变形运营隧道影响实测分析

随着城市建设的发展,部分运营隧道结构历史上已经出现了一定程度的变形,结构状况不良,比其他位置的隧道更容易受基坑开挖或辅助措施施工的扰动。某工程深基坑紧邻运营地铁隧道6 m,距离在建地铁隧道12 m,基坑开挖深度14.9 m,坑底位于隧道以下,施工过程严格遵循“时空效应”理论。本文通过对深基坑不同施工阶段的隧道沉降、收敛及水平位移的监测分析,提出了必要的控制措施,使得隧道变形控制在允许范围之内,为日后类似工程提供借鉴。

The Field Test Analysis on Effect of Adjacent Excavation of Deep Foundation Pit on Deformed Metro Tunnels

With the development of city construction, there was some deformation and poor structural condition on the part of tunnel structure in its history. Such part is more susceptible to disturbance from foundation pit excavation and supporting measures construction than normal tunnel. A deep foundation pit is 6m adjacent to metro tunnel, the distance to subway is 12m and the excavation depth of foundation pit is 14.9m, which located below the bottom of tunnel. The theory of time-space effect is the most important base for the construction process. Based on the monitoring and analysis on the convergence of tunnel settlement and horizontal displacement of the deep foundation pit in different construction stages, necessary control measures are put forward, which would make the tunnel deformation controlled within the allowable range and can serve as reference in the future for similar engineering projects.