Seismic Response Analysis Of Long-Span Hybrid Girder Cable-stayed Bridge And Its Opyimization Of Damper Parameters

The bridge,as the research object of this thesis,is a hybrid beam cable-stayed bridge of 530m main span.The full-bridge finite element model of this bridge is established by using finite element method.Meanwhile,the dynamic characteristics and seismic response of long-span cable-stayed bridge are analyzed.Main contents are included as follows:(1)This thesis briefly introduces main features and the development history of the hybrid beam cable-stayed bridge.Besides,it analysizes the characteristics and causes of some common bridge damage;(2)This thesis summarizes theoretical formula of several main seismic response analysis methods for bridges,such as static method,response spectrum method and dynamic time history analysis method.And their respective scope and advantages or disadvantages are discussed in the thesis;(3)The build process of the finite element model of the cable-stayed bridge is described in detail,and the dynamic characteristic results of the pile foundation model and the no-pile foundation model are calculated.What’s more,the effects of pile-soil-structure interaction on the self-vibration characteristics of the structure are researched through comparative analysis;(4)The seismic response of the long-span cable-stayed bridge is calculated by using the time-history method,the influence of pile-soil-structure interaction on the seismic response of long-span cable-stayed bridge was discussed by comparative analysis.(5)The influence of traveling wave effect on the seismic response of long-span cable-stayed bridge is studied by using multi-point excitation method.And the response of longitudinal displacement of the main tower top and the main beam,the response of main tower bottom internal force are analyzed under the condition of five kinds of seismic wave velocity conditions.(6)The influence of different parameters of longitudinal viscous dampers on the seismic response of the long-span cable-stayed bridge is studied through nonlinear time-history analysis method.In addition,the damping coefficient and damping index of the damper are optimized,and a set of viscous damper parameters suitable for the cable-stayed bridge is proposed.