Seismic Response Analysis And Isolatated Measure Research For Dongting Lake Bridge

Dongting lake bridge on new-built Jingzhou-Yueyang railway is the first triple-tower double-main-span railway cable-stayed bridge in the world, the span arrangement is(98+140+406+406+140+98)m.Box-truss composite structure main girder is used in this bridge.This paper mainly introduces the development course of the cable-stayed bridge,the seismic damage of the earthquake and the survey of the seismic isolation device.Four theories of bridge seismic response analysis are introduced in this paper-- static method, response spectrum method, dynamic time-history analysis method,and pseudo excitation method. On the basis of that, the thesis takes the Dongting Lake Bridge as an example, and by using finite element software establishes finite element model of the whole bridge.The elastic time history analysis of the bridge is accomplished and the isolating effect is discussed. The main work is as follows:(1) Establish its spatial finite element full bridge model by using Midas/civil software to,and calculate the dynamic characteristics of the bridge.Its dynamic characteristics are analyzed.(2) By using the time history analysis method, the seismic response of longitudinal and transverse and vertical seismic responses are calculated.(3) The energy dissipation of the cable-stayed bridge is analyzed. The results show that the elastic and viscous dampers can effectively reduce the displacement and internal force response of pylon and girder of cable stayed bridge.(4) Respectively on the device, an elastic and viscous dampers main design parameters is discussed in this paper. Analysis of the elastic stiffness, damping coefficient, velocity index influence on seismic response of the structure, aseismatic design of the cable-stayed bridge provides a theoretical basis. Finally, according to the analysis results, put forward the suggestion value of damper parameters of bridge.