Seismic Response Analysis And Vibration Mitigation Research For Cable-Stayed Bridges

It is well known that the large-span bridges which are heavily invested in are the key parts of transportation system,and have important influence on the national economy.Once destroyed,it will lead to huge economic loss and heavily influence on the work of salvage and rehabilitation of disaster area.So it is important for seismic design of cable-stayed bridges to ensure its seismic safety.This paper outlines seismic design methods for cable-stayed bridge, while it takes Yuanjiang bridge of Changde as the engineering background, the main study is: the method of dynamic analysis modelling of cable-stayed bridge, the seismic response analysis of cable-stayed bridge, a method of Vibration Mitigation Research for Cable-Stayed Bridges and the theory of bridge seismic design. the main contents include:(1)Summarizes the simulation methods of cable-stayed bridge girders and analyse the mechanical principle of Triple-girder model. It is illustrated that the triple-girder model is appropriate to model cable-stayed bridges with open sections.(2)Combined with specific example-- Yuanjiang Bridge seismic study, this paper makes the seismic risk analysis of the bridge, discusses two methods for seismic wave,and a detailed calculation of the dynamic characters, response spectrum and the time-history analysis.(3)According to the stress-strain relationship of steel and concrete,and plane-section assumption,a C++ program is compiled to calculate the axial force-moment-bending ratio relationship of the tower section under axial force.Then a two-line skeleton curve model of the reinforced concrete section of the bridge tower is drawn from the relationship curve, which is used to define the restoring force model of the plastic hinge of the bridge pile under strong earthquake motion.Take the analysis of the plastic hinge of the bridge tower under strong earthquake motion and the seismic analysis based on the elastic-plastic fiber beam-column element.(4)Discussed the influence of longitudinal elastic constraints between the tower and beam on the seismic performance of cable-stayed bridges(5)Discussed the current bridge seismic design theory and summed up the difference of bridge seismic design specifications between China and US.The conclusion of this paper for the bridge seismic design can be used on other similar bridge seismic analysis and has some reference values。...