天津某基坑开挖引起隧道变形的有限元计算

FEM Calculation of the Tunnel Deformation Caused by the Excavation of Foundation Pits in Tianjin

天津某深基坑工程,由于其深度较深,周围环境复杂,并且紧邻地铁,因而在深基坑施工作业过程中有必要对周边隧道变形进行计算和监测。针对基坑的特点和土层的各项参数,运用有限元方法,计算隧道的竖直和水平位移,并根据计算结果制定了合理的监测方案。计算结果表明,由于基坑开挖,会造成周围隧道的竖直方向变形和水平方向变形,且越靠近基坑开挖位置位移越大,位移以最大值点为中心,朝隧道两端方向减小。隧道变形仍在安全范围之内。计算和设计成果为基坑施工过程中工程的安全性提供了可靠的保障,可为类似工程提供参考和依据。

A deep foundation pit engineering in Tianjin was taken as an example because of its depth and the complex surrounding environment,it is necessary to monitor the deformation of the surrounding tunnel in the process of deep foundation pit construction work. According to the characteristics of the foundation pit and the parameters of the soil,FEM calculation is used and the reasonable monitoring scheme was developed based on the results. The results of FEM calculation show that the excavation of the foundation pit causes the vertical and the horizontal deformation of the surrounding tunnel. The displacement increases with the distance between the tunnel and the foundation pit. The point at the center has the maximum displacement. The displacement reduces toward opposite ends of the tunnel. The research results could provide reliable guarantee for the engineering safety in the construction process of the foundation pit and reference and basis for similar engineering.