Study Of Mechanics Characteristic Of The Fabricated Railway Tunnel

From the development of prefabricated technology, the study of prefabricated technology in underground engineering develops from two sides. One is part prefabricated technology and the other is completed prefabricated technology. Using the prefabricated component not only improves the quality of engineering, but also abridges time limit for a project and reduces the cost. At the same time improves the industrialization extent of tunneling. It can improve the environment of construction obviously. Especially, to railway tunnel, it not only reduces the cost but also improves the quality of tunneling. So it is necessary to research the mechanics characteristic of the fabricated railway tunnel.Using mathematic analysis method analyses the different tie-in" computation mode of fabricated lining railway tunnel. The thesis studies the contents as follows:Amended rigidity method can simulate the mechanism by changing the rigidity coefficient, but it is difficult to choose the rigidity coefficients.Beam-spring model can simulate the tie-in by predigesting the tie-in of lining to three springs including axial spring, tangent spring and resisting bending spring, but there is a defect that it can' t simulate the partiality of bolt in lining.Beam-tie-in model can simulate the mechanism, but when we ensure the rigidity of spring, we have some trouble. If we can accurately ensure the rigidity coefficient, the result of mathematic analysis method can approach the fact accuratelyBy applying contact mechanics theory, we can deal with the lining and lining as contact problem of two bodies. Using pretension bolted solid finite element simulate bolt at linings. Thus not only considers perpendicular rigidity but also considers the tangent contact rigidity. This model is more closed to reality.There is cavity situation because of incorapletion of lining backpressed concrete. This thesis appraises the safety and stability of lining in nine kinds of cases through applying finite element method. Consequently, when there are cavities behind of lining, the stability of the invert must be considered especially. There must be some measures to prevent instability.