The Seismic Response Analysis Of Long-Span Composite Beam Cable-Stayed Bridge

Once the cable-stayed bridge, a traffic hub project, was damaged in an earthquake, thedisaster relief work and reconstruction would be seriously influenced. Therefore，to theseismic response of long span bridges, it was the scientific basis to establish reasonableseismic resistant system. This paper analyzed the spectrum response、the time-history and thetraveling wave affects of the cable-stayed bridge, according to a large span cable-stayedbridge as the engineering background. The main work were listed as follows：(1) This paper established a spatial finite element model of the bridge based on thetheory of finite element, and considered the impact of the pile-soil-structure interaction onstructural dynamic characteristics. Its results indicated that the pile-soil-structure interactionhas significant influence on the dynamic characteristics.(2) This paper analyzed the responsespectrum of cable-stayed bridge, and the seismic response analysis of the bridge by inputtingresponse spectrum curve along the longitudinal, transverse and two types of combined groundmotion (longitudinal&vertical, transverse&vertical). The results indicated that the effect ofvertical earthquake on the structure could not be ignored. The impact of damper on structuralearthquake response was analyzed. It came to that the viscous damper could effectivelyreduce the displacement response and internal force response of cable-stayed bridge, andincreased the seismic capacity and durability of cable-stayed bridge.(3) Based onconsidering the influence of geometrical nonlinear on the structure, this paper analyzed thetime-history analysis of cable-stayed bridge. It indicated that the longitudinal seismicresponse of cable-stayed bridge was the control factor of anti-seismic design, by analyzingand summarizing the results. Compared the results of time-history analysis and the responsespectrum analysis, we knew that the calculation results of response spectrum were bigger, soseismic checking computations should be combined with the time-history analysis.(4) Usingthe large mass method，this paper analyzed the time-history analysis included in the travelingwave effect, studied on the influence law of different velocities on long span cable-stayed,and compared the results with continuous incentive. The results indicated that travelling waveanalysis is necessary for long span cable-stayed bridge.The conclusions of this paper can be used as the basis of seismic design of such kindsbridge and is useful for directing seismic response analysis of other kinds bridge.