Study On Seismic Resilience Assessment Method For Bridges

With the rapid development of Chinese economy and urbanization,the threat of earthquake disaster to the large cities become more severely,and so the seismic resilience of urban engineering system after the earthquake has been paid more and more attention.To establish the seismic resilience evaluation theory and methods for urban engineering system become urgent needs.Bridge is an important part of the urban lifeline system,and its seismic resilience after the earthquake has an important influence on the city's recoverable ability.Through the study,two kinds of post-earthquake seismic resilience evaluation methods are established for bridges: the first method is suitable for evaluating the seismic resilience of a specific bridge,and the concept of seismic resilience curve is put forward;the second method is suitable for evaluating the seismic resilience of a kind of bridges,and the concept of seismic resilience matrix is proposed.The main research of this paper is as follows:1.Introduces the background and significance of the topic,and describes the current situation of the research on resilience.2.A seismic resilience assessment method is proposed on account of bridge components vulnerability curves and retrofit approaches,the concept of seismic resilience curve is put forward,which could reflect the relationship between seismic resilience and earthquake size.The resilience index considered both retrofit time and building time,which could reflect the efficiency of resilience.This method is suitable for evaluating the seismic resilience of a specific bridge.3.Based on the overall vulnerability of the bridge,the repair time and the building time,another seismic resilience evaluation method is presented.In this method,the concept of seismic resilience matrix is proposed,which could reflect the seismic resilience of bridges in different intensity areas.This method is suitable for evaluating the resilience of some kind of bridges.The seismic resilience of beam bridges and arch bridges in Wenchuan is analyzed,and the resilience curve and resilience matrix of two kinds of bridges are given and compared.4.A finite element model of reinforced concrete beam bridges is established,the moment-curvature relation of pier,the vibration characteristic cycle of the bridge is analyzed.The nonlinear time history of the model is analyzed,and the vulnerability curves of the pier and the bearing are obtained.The seismic resilience of the bridge is analyzed with the first method proposed this paper,and the seismic resilience curve of the bridge is given and evaluated.