Numerical Simulation Analysis and Engineering Applications on the Double-Side-Wall Heading Step Bench Excavation of Large-Cross Section and Shallow Tunnel

Abstract

With the pace accelerating of development of urban rail traffic in large and medium-sized cities, urban subway and railway lines need to construct shallow and large-cross section tunnels and especially large-cross section tunnels. Large-cross section tunnel constructions make big influence on the surrounding buildings, roads and environment. How to build underground tunnel fast and safe in the downtown has become an problem which needs to be solved urgently. This article is for the technology of city large-cross section and shallow buried-tunnel, relying on the phase 1 of rail transit no.2 in Changsha, which combined with construction characteristics of the excavation method, double-side-wall method and step method, numerical simulation analysis on influence of the large-cross section tunnel disturbance in the surrounding rock, and provides the necessary technical support.