Research On Mechanical Characteristic Of Fabricated Lining Of High Speed Railway Longspan Two-Line Tunnel Constructed With Mining Method

At present, the fabricated lining is not frequency used in tunnel of mountain ridge, and it is mainly applied to shield tunnel, and it is more and more developed in technology. The lining mode is useful for tunnel of mountain ridge, in our country, most railway tunnels are constructed with mining method, while use of prefabricated component not only improves the quality of engineering and accelerates the construction, but also reduces the cost and improves the environment of construction. At the same time, this is the necessary trend of the mechanization of tunneling. So the fabricated lining has broad application foreground in railway tunnel constructed with mining method, therefore, it is necessary to research on the basis of mechanical characteristic of the fabricated lining of tunnel constructed with mining method.Based on the models designed and calculated by tunnel home and abroad, mechanical characteristic of the fabricated lining of tunnel constructed with mining method is researched by using numerical simulation method, the thesis studies the contents as follows:(1) The "load-structure Method" and "surrounding rock structure Method" adapting to the calculation of structure fabricated railway tunnel constructed with mining method are proposed.(2) Section shape of tunnel that is suitable for fabricated lining is fixed through optimization design.(3)Five kinds of schemes are brought forward, and the best scheme for component partition that is suitable for full prefabricated lining structure is found.(4)The stress character of lining structure in different fabricated modes are analyzed.(5)The dynamic state of tunnel construction is modeled by FEM.Through over several respects analysis of the results, the large span twin-track tunnel of the high-speed railway made of mine method construction, using the prefabricated lining Structure , has the relatively suitable section form and the proper segment assembling method. As for the grade-five wall rock, the thickness of the lining segments can adopt 45cm and the alternative joint assembly mentioned in program five can be applied into the segment assembly (where there are two rocks on the vault, two for one side wall and three for the other side wall, and three for the inverted arch).