ABSTRACT

In this paper, the process of two side heading method for the construction of the transitional large span tunnel in Gongji section of No2 line of Guangzhou Metro has been simulated with the application of ANSYS V5.5 FEM program. The 3d computation yields the stress state of surrounding rock, distribution of plastic zone in surrounding rock, ground subsidence and internal forces of the tunnel support structure during each period of construction with NATM. Finally the time of building secondary lining and the part length of removing the temporary support while building the secondary lining have also been analyzed.