Study On Seismic Performance Of Large Span Steel Arch Bridge With Vibration Reduction Devices

Construction of the project structure is advancing along with the development of ournation’s economical development. Because of the complexity mechanics capability, the hugeproject structure has a limitation on its criteria application. Damage of the bridges in all previousearthquakes definitely unfold the deficiency and insufficiency of seismic technology, a series ofunsolved issues about analyzing the quake-reaction and designing seismic structure of complexsteel arch bridge needed to be discussed. After suffering the tragic quake in Osaka and Kobe,a high attention have been focused on the serious shaking phenomenon of the steel structurebridges. This project details cosmically steel arch bridges which crossing the sea, however, itneeds further study on how to improve the capability of seismic performance considering theeconomical factor.Based on illustrating the fundamental theory of seismic reduction/isolation in currentdomestic research, the essay compares computational models of and theories on commonseismic reduction/isolation equipment, and systematically summarize various factors that affectthe design of seismic reduction/isolation, and gives a specific analysis of seismic response tothe steel arch bridge which span is381m.The space shape of the steel arch bridge is asymmetry, not only the surface of the bridgelist entad with a angle of1:5, but also the jumping-off point and the endpoint of both sides arecurve, this article introducing finite element analysis software, ANSYS, to build anappropriately three-dimensional analyzing model.Assuming the lower component as elasticunit in order to analyze the ant-seismic performance of the upper structure. In order to studyhow the position of reduction dampers to do effect on the seismic performance, fixed theseismic reduction dampers in vertical and level inclined strut separately.This paper firstly analyzed the internal force of the steel arched bridge under deadweightcondition, and discussed the influence of the damper to the steel arched bridge component under static state. Secondly, it gave a specific study on the self-vibration dynamic performance of thesteel arched bridge, and then compared the frequency of the original bridge to the one using theattenuator. Finally, carried out a series of research to the internal force of steel arched bridge, inorder to get a conclusion for response performance in an earthquake of three kind of plans: theoriginal bridge, the vertical reduction of shock bridge and the crosswise reduction of shockbridge.The result indicates: Because of the spatial asymmetry, the effect of the earthquakereduction of the two cases according to the difference location of the damper is different to thesemisic response of the top structure under the different direction earthquake waves. Case Oneis better than Case Two in the effect of the seismic reduction under the axis earthquake waveand the result is reverse rightly under the wave upright to the bridge. During the earthquake, theabsorption of the damper to the energy may reduce the bridge primary component the internalforce and the distortion, guarantee the safety handling performance of the bridge whenexperience earthquake. When considering the plasticity distortion and the damper together, themoment of the main beam may reduce30%~40%.