Analysis Of Double-deck Tunnel Dynamic Response Under The Train Load In The Subway

In the 21st century, with the development of urbanization, development and utilization of underground space of the scale has been expanded, with the growing size of the subway, the close range's tunnels will be appear inevitably in subway. In this paper, based on the main theory of the interaction between tunnel structure and rock, according to using ANSYS to establish finite element models and study the dynamic responses of the close range and double-deck tunnels under the train load.First of all, in this article, the principle of dynamic finite element analysis the underground structure of is summarized, the basic theory of finite element is describes, the establishment of dynamic equilibrium equations is introduced, as well as underground structures and to solve elastic-plastic constitutive model.Secondly, in view of the characteristics of train vibration load in subway, simplified the dynamic analysis model of a train-track system, simulated and calculated the train load of the effect on the bottom of track bed. The method aims at a single cave which is be parted as a single double-deck tunnel by a clapboard to study, finite element model of a modal analysis to determine the damping parameters of the system and the dynamic analysis of time integration step. Use the finite element model to calculate the static field, on this basis, the use of two-dimensional elastic-plastic dynamic finite element method analysis of vibration response of the train, the calculation of rock material using DP model. Finite element method design two cases and complete the simulation, simulated the dynamic response of structural system of the tunnel under dynamic load up and down and alternate dynamic load in the double-deck tunnel parted a single cave by a clapboard.The results of calculation are shown that: (1)The stress of the linier has increased in various degrees under trains' dynamic load in the subway, but it is not large relative the static stress and the initial stress is still a major factor of security in the lining. (2) The displacement caused by the trains' dynamic load in the subway is not large. (3) Compared to other parts of the lining in the tunnel, the effect of the middle clapboard and the inverted arch caused by the train's dynamic load is significant. (4)The dynamic and static stress of the lining in the case of the rock strengthened is less than un-strengthened under the dynamic load of action of the train. The calculated results are value for the design of the subway with reference...