新建基坑对既有下卧地铁隧道的影响研究

The influence of new-built deep excavation on the underlying tunnel

基坑开挖会引起下卧隧道周围的土体应力变化,使下卧地铁隧道产生变形,对隧道的稳定性产生影响。以郑州地铁1号线隧道上开挖基坑为背景,采用ABAQUS有限元软件对基坑下部隧道顶部变形和基坑外墙变形进行计算。研究表明:基坑开挖引起隧道产生竖向位移,距离基坑纵向距离越远,隧道的隆起量越小。外墙变形沿着深度方向先增大后反向增加至一定的值,最后减小至0。

Excavation of the deep excavation will cause the soil stress change around the underlying tunnel,which will cause deformation of the lower subway tunnel and affect the stability of the tunnel. Based on the excavation of the deep excavation on the tunnel of Zhengzhou Metro Line1,the ABAQUS finite element software was used to calculate the deformation of the top of the tunnel and the deformation of the external wall of the deep excavation. The research shows that the tunnel is subject to vertical displacement due to the excavation of the deep excavation. The farther the longitudinal distance from the deep excavation is,the smaller deformation of the amount of tunneling is. The deformation of the outer wall increases first in the depth direction and then increases to a certain value in the reverse direction,and finally decreases to zero.