Assessment Of Seismic Vunerability And Economic Loss For Self-centering Bridge Structures

In recent years,large earthquakes occurred frequently,for example,the Northridge earthquake in southern California in 1994;the maginitude 7.2 earthquake in Hanshin,Japan in1995;7.6 in 2006,Earthquake occurred on May 12,2008,Wenchuan Country,Sichuan Province,Chian.In 2011,a magnitude 9.0 earthquake and a tsunami occurred in the northeastern part of Japan,all of which resulted in significant casualties and property damage.Bridge is the hub of the transportation system,is an important part of the lifeline project,in the modern social life and work play an increasingly important role.After the earthquake,the destruction of the bridge led to the disruption of the traffic network,which not only will affect people's normal travel and economic operation,but aslo to the community has brought serious economic losses,and will affect the earthquake relief work,thereby increasing the earthquake disaster.Therefore,it is important to study the damage of bridges under earthquake action.In this paper,the seismic vulnerability and seismic risk of reinforced concrete continuous girder bridge are systematically studied based on the “performance-based seismic engineering” of the US Pacific Earthquake Engineering Research Center(PEER).The main contents and conclusions of this paper are as follow:(1)Pushover of the traditional ductile bridge are performed,and a method for estimating the median curve of incremental dynamic analysis based on the push curve is proposed.(2)Probabilistic seismic demand analysis of four-span continuous self-centering bridge is carried out.Respectively,the piers displacement ductility(?)and the bearing displacement(D)are selected as the respective demand parameters,and the peak ground acceleration(PGA)is selected as the ground motion strength parameter.And 19 ground motion-structure sample pairs are selected for earthquake excitation.Then incremental dynamic analysis curves can be obtained by linear regression analysis of the bridge probability seismic model.The results show that the median curve of the incremental dynamic analysis based on the pushover anlaysisis in good agreement with the rigorous incremental dynamic analysis.(3)Seismic vulnerability analysis of self-centering bridge piers with energy dissipation devices was carried out.(4)Using the fitted vulnerability curve to analyze the economic ioss of the four-span countinuous bridge structure,the rationality of the incremental incremental power analysis in the economic evaluation is obtained,and the self-resetting bridge is superior to the traditional bridge in the economic damage assesment.