基坑开挖对既有双向隧道衬砌的影响分析

ANALYSIS OF THE IMPACT OF FOUNDATION PIT EXCAVATION ON EXISTING BI-DIRECTIONAL TUNNEL LININGS

为研究基坑开挖对既有地铁隧道管片位移以及围岩压力的影响,结合西安市某地铁站基坑开挖实例进行数值模拟分析。文中采用ABAQUS有限元软件,考虑隧道不同间距和隧道与基坑不同间距的状况,研究在既有双向隧道情况下隧道的水平位移和竖向位移变化。研究结果表明,随着左右两侧衬砌的间距不断增加,左侧衬砌仰拱向上移动的位移不断减小,右侧衬砌拱顶向下移动的位移不断增大;随着衬砌距基坑的距离不断增大,左侧衬砌仰拱的竖向位移减小,左侧衬砌拱顶的竖向位移增大。

To investigate the impact of excavation on the displacement of existing metro tunnel segments and sur-rounding rock pressure,a numerical simulation analysis was conducted based on the excavation of a foundation pit at a metro station in Xi'an.Using the ABAQUS finite element software,the study examined various scenarios involv-ing different distances between tunnels and between the tunnel and the foundation pit,focusing on the horizontal and vertical displacement changes of the tunnel in a bi-directional tunnel configuration.The results indicated that as the spacing between the left and right linings increased,the upward displacement of the left lining arch decreased while the downward displacement of the right lining arch increased.Additionally,as the distance from the linings to the foundation pit increased,the vertical displacement of the left lining arch decreased,while the vertical displacement of the left lining crown increased.