Comparison of Chongqing Metro Station Construction Method in Super-large Section Tunnel of the Stratigraphic Strata

Considering the special geological conditions of stratigraphic strata in Chongqing City, the super-large section and remarkable influence of the construction, where the metro station is constructed with subsurface excavation method, a numerical calculation model is established which adopts the double-layer superimposed initial support arch-cap method, doublesided heading method and CRD method, in order to analyze the adaptability of construction methods, and compare the actual engineering economic indicators. The results show that all the indexes of the double-layer superimposed initial arch-cover method can meet the control standards, and the convergence shape around the tunnel is better controlled by using each of the 3 construction methods, and the safety of the lining structure is also higher. The double-layer superimposed construction method adapts to the geological conditions and economic requirements of Chongqing area due to its obvious advantages such as large working face, high efficiency, less working procedures and safe construction, therefore has better economic applicability. In the construction of super-large cross-section underground excavation station in stratigraphic strata of Chongqing City, the double-layer superimposed method is recommended.