Abstract：
Through the investigation and summary of design documents for the existing 15 shield tunnels in Shanghai, the prevailing defects in existing tunnels are categorized and analyzed, and the prevention and treatment measures for tunnel issues are proposed. The design and selection of protection enclosures in an open-cut section, along with structural engineering scales and geometric design parameters of shield tunnels, are statistically analyzed, and some suggestions about the selection and insertion ratio of an enclosing structure in an open-cut connecting section are put forward. Additionally, a calculation model and method of parameter calculation for open-cut structures are determined. The geometric parameters of overburden, minimum curve radius, minimum distance between line centers, and maximum gradient are analyzed in detail, and a method to determine the plane dimension of the launching shaft and the key techniques for shield launching and arrival are concluded.
2014, Vol. 51 