Seismic Performance Of Existing Concrete Continuous Beam Bridge Strengthening Research

The codes for seismic designs of highway bridges have been applied for three generations at present in China. As the seismic design methods have been developed and updated, there are seismic safety hazards of varyingdegrees for the bridgeswhich were designed by the former methods or which had no seismic designs. Therefore, the main contents are as follows:●The three-generation seismic codesapplied in1997,1989, and2008are researched. Especially,the1989Specifications and the2008Guidelines are analyzed and compared in aspects of seismic fortifications, design methods, comprehensive influencecoefficient, ductility seismic design, seismic isolation design, seismic measures, and so on.lt is concluded the major advances of ideas and methods of current codes,and the defects of previous codes are illustrated.●The approachesaboutbridge seismic performance evaluations at home and abroad are analyzed. Mainly, there are four-category approaches:the emergency seismic performance evaluation approach based on field inspections, the speedy seismic performance evaluation approach based on pre-existing information systems, the seismic performance evaluation approach based on deterministic calculations, and the seismic performance evaluation approach based on probability theory.By comparison, the suitedbridgeseismic performance evaluationapproach for pre-seismic detailed evaluation is obtained.●We investigate the characteristics of thecrete bridges and4representative bridges are extracted on the basis of bridge characteristics. Then, the calculation procedure of the seismic performance evaluation approach based on deterministic calculations is established. And,it is concluded that the seismic defections of representative bridges according to the capacity-demand ratios.●The seismic retrofittechnologies at home and abroad are researched.The concreteseismic retrofitstrategies for municipal bridgesare presented.And,superstructureseismic retrofit measures, substructureseismic retrofit measures, isolation seismic retrofit measures, andcomprehensive seismic retrofit measures, which are suited for municipal bridges, are presented.