Study On Supporting Of Segment Structure During Constructing Traverse Channel Between Two Shield Tunnels In Water-enriched Sandy Stratum By Freezing Method

Based on the traverse channel construction applying freezing method in Wuhan Yangtze River highway tunnel, 2D theoretical calculation method and 3D numerical simulation are used to study the supporting pattern of shield tunnel segment structure constructed by freezing method in water-enriched sandy stratum in order to deduce the calculation formula of supporting forces under water-soil load and frozen-heaving force, which can more effectively support the shield tunnel segment structure in traverse channel during excavation. Firstly the formula of supporting forces is deduced by modified routine method, then 3D numerical simulation is used to modify the formula above so as to deduce the final formula. The main research contents of this paper are as follows:1. The main method and related theory for the design of shield tunnel segment structure is reviewed to generalize the analysis method for internal force of segment structure, like routine method, modified routine method, multi-hinge ring method and beam-spring model method. The principle of force method is finally used to deduce and proof the formula of segment structure inner force under stratum water-soil load.2. The open section of the lining segment is simplified as open-ring during 2D theoretical calculation to deduce the calculation formula of supporting forces under stratum water-soil load and frozen-heaving force, which considers the shearing action on the cross section.3. 3D numerical simulation is used in the traverse channel construction applying to freezing method of the shield tunnel, which concluded the affect to tunnel segment structure and supporting for segment structure in construction by freezing method.4. The size and distribution of the shear force on the cross section of the open-lining segment is studied, as well as the influencing factor of supporting forces, in order to deduce the modified the formula of the supporting forces.Conclusion is draw through the above research as follows:(1) The frozen-heaving force has influence on inner force and deformation of tunnel segment structure, supporting force has something to do with the frozen-heaving force and opening condition of segment structure.(2) Based on the 2D theoretical calculation method and 3D numerical simulation, the calculation formula for supporting forces is of some use for the support design in tunnel segment structure and of some engineering values...