Influence of Excavation of Loess Tunnel on Stability of Adjacent Existing Tunnels

This study investigates a project for new railway tunnels constructed adjacent to existing tunnels in the Loess Plateau region of Taiyuan, Shanxi Province, China. A comprehensive empirical evaluation method and three-dimensional Lagrangian numerical simulation were used to analyze the effects of newly built tunnels on the stability of existing tunnels. Research conclusions are listed as follows. Empirical evaluation method is used to study the construction of the newly built tunnel, which is located within the restricted range of the two existing tunnels and the caution range. When the newly built tunnel is within the restricted range of the existing tunnel, the smaller the distance between the two tunnels, the greater the influence on the deformation of the existing tunnel. When the newly built tunnel is located within the caution range of the existing tunnel, the tunnel contains maximum disturbance in the middle of the axis of the existing tunnel. The results provide a reference for future research on similar adjacent construction. (paper)