Analysis And Enhancement Of Cable-Stayed Bridge Seismic Performance

Taking into account the considerable costs invested in the construction of cable-stayed bridges and the risks imposed by the earthquake events,it is up for this research to come out with appropriate methods,which may lead into a considerable reduction of the risk of collapse for the structures during the events of the earthquake.In this study,the seismic performance of existing cable-stayed bridge has analyzed with possibilities for its improvement being a significant point of discussion.The methods for seismic improvement of the bridge have been put into details availing the mechanism of enhancing the seismic performance of the bridge.In the analysis,the 3D finite element model of the reference bridge was created in SAP2000 software to perform the bridge seismic response analysis.The retrofitting strategy has been intensely discussed in this study as the enhancement strategy of the seismic performance of the bridge.Then the nonlinear time-history method of analysis is carried out to analyze the response of the cable-stayed bridge under the three components of the El-Centro seismic event under three proposed structural configurations.In the first configuration,the seismic response of the reference bridge in its original design parameters is performed under dead and seismic loads followed by subsequent analysis deploying retrofitting the bridge with ERS systems that involved a fluid viscous damper at tower deck connections and a lead rubber bearing isolator at abutments locations.Comparison analysis has performed for the bridge key variable parameters.Comparison analysis of the numerical results indicates that there is a remarkable improvement in the bridge seismic performance under application of the retrofitting strategy.The numerical results indicate FVD's is a useful tool in controlling the internal forces in the bridge resulted from the effects of earthquake events;notable reductions were observed in the bending moment at the pylon base,base reactions,and shear forces at pylon bottoms as compared to the nonretrofitted bridge.Furthermore,the base isolation under LRB's has indicated a significant reduction in the destructive effects of the earthquake on the referenced bridge;the LRB's has reduced deck maximum moment,pylons deflection at the top,maximum deck deflection at mid-span,pylon bottom moment and overall input energy into the structure.Hence,the overall seismic performance of the bridge has greatly enhanced under isolation strategy.