临近地铁隧道基坑开挖的数值模拟分析

临近地铁隧道的基坑开挖必定会对隧道产生影响,同样隧道的存在对基坑的变形也有一定作用。通过对上海某基坑工程应用FLAC3d软件进行数值模拟分析,研究发现,基坑开挖卸载后,地表发生沉降,基坑内土体发生隆起,其中靠近隧道区域隆起值最大;隧道开始整体向基坑方向侧移,但是上下、左右特征点位移量并不一致,隧道产生不均匀应力,特别是上下方向可能存在拉应力。

Numerical Analysis of the Deep Excavation near a Metro Tunnel

The deep excavation near a metro tunnel will impact the performance of the tunnel itself whereas the tunnel will affect the deformation of the excavation support system. The three dimensional numerical analyses are performed on a deep exca-vation in Shanghai using FLAC3D in order to provide guidelines for the design construction and monitoring of the proposed projeer. The results indicate that, after the excavation, bottom heave and ground subsidence is observed. The maximum bottomheave is near the metro tunnel. The tunnel has a global lateral movement towards the excavated area with a non-uniform movement. Tension stress might exist at the top as well as at the bottom of the metro tunnel.