基坑开挖邻近隧道水平形变位移规律

基于水平基床系数的变化提出“水平形变位移”这一概念,将隧道拱腰水平位移可分为三部分,利用PLAXIS 3D有限元软件进行分析,并拟合得到最大水平形变位移与基坑宽度、水平距离的关系公式。研究结果表明,水平形变位移随隧道与基坑水平距离的增加呈指数关系降低;当水平距离大于一倍基坑深度时不考虑基坑宽度的影响。本研究所推导的水平形变位移计算公式可用于计算临近基坑开挖的隧道水平收敛值、隧道拱腰的水平位移、隧道附近的水平基床系数。

Law of horizontal deformation displacement of tunnels due to adjacent excavation

The horizontal displacement of the tunnel hance was divided into three parts. Based on the change of horizontal coefficients of subgrade reaction, the paper proposed the concept of “horizontal deformation displacement”, which was analyzed by the PLAXIS 3D. And the correlation formula between the maximum horizontal deformation displacement and the foundation pit width and the horizontal distance was obtained by fitting. The results showed that the horizontal deformation displacement decreased exponentially with the increase of the horizontal distance between the tunnel and the foundation pit, and the influence of the foundation pit width was ignored when the value of the horizontal distance was greater than the depth of the foundation pit. The formula derived in this paper could be used to calculate the horizontal convergence value of the tunnel adjacent to the excavation, the horizontal displacement of the tunnel hance, and the horizontal coefficients of subgrade reaction near the tunnel.