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