Research On Optimized Composition Of Segments For Shield Tunnels

As an important link in shield tunneling, the selection and the assembly of segmentsinfluence the final quality of the tunnel. In the construction process, the shield drives withbackup force of the erected segments, and the emerged deviation in the fitting of designedtunnel axis and actual axis is an important indicator of the construction. Based on theresearch on characteristic and assembly process of segments, this thesis mainly establishesthe optimized composition and ring selection method of segments. The details are asfollowing:Through analyzing the designed tunnel axis, deduce calculation formulas respectivelyfor the line, circle and connecting curve, which appear in the designed tunnel axis, intwo-dimensional coordinates system. Then, integrate the calculations of horizontalalignment and vertical alignment with the parameter of mileage in order to calculate thethree-dimensional coordinates of DTA.Through the analysis to geometrical characteristic of segments, establish themathematical model of single segment in order to describe its basic information.Analyzing the process of assembly for segments in the actual construction and consideringthe parameter of erecting position, establish the mathematical model for composition ofseveral segments, thus deduce the calculation formulas for their position and pose.Analyze the factors that must be considered in the assembly of segments. Simplify theresearch object through combining these factors into two main factors using theirrelationship. According to the principles of assembly, establish method and process ofassembly. Establish the function through comprehensively considering the influencingfactors of selection and assembly of segments. The function can be used to optimize theprogram of the composition for segments in order to guide the constructors. Program theselection and assembly of segments software using visual basic.net.