Method of seismic reinforcement of the existing bridge system

Compared with requirements of the seismic performance of bridges under the current seismic codes for bridges design,the current majority of bridges in-service roads have seismic deficiencies in different levels.These deficiencies had an adverse impact on the performance of bridges of road network,once the disastrous earthquakes occurs,the direct and indirect economic losses is very huge,and it is unable to meet the expected seismic performance requirements,so the study of seismic retrofit of existing bridges is imminent.In this paper,based on the basis of investigation of the existing bridge building’s history,seismic design features and vulnerable component of bridge under earthquake,from the point of view of the bridge structure system,we investigate many of economic,effective retrofitting measures,and promote the development of seismic retrofitting technology for bridges.