In order to ensure the seismic safety of existing bridges,a systematic rapid evaluation method for the seismic performance of existing highway bridges is proposed based on the previous researches and the seismic codes or standards of highway bridges in China.This method is applicable to the girder bridges with span less than 150 m and without high piers on good sites.It mainly includes three aspects:the risk assessments of deck falling,pier details and pier ductility.For the bridges whose seismic fortification does not meet the requirements of the current zoning map or meets the requirements but are designed according to the"89 Specification"or without considering the seismic design,the strength requirements under E1 seismic effect and the deformation capacity under E2 seismic effect for the piers are complementally checked.Then the system process of rapid seismic performance evaluation for highway bridges is proposed,and the demonstration study and application of five bridges built before the implementation of'08 Guidelines'are carried out.The results indicate that only one bridge has the risk of deck falling;most piers have the details do not meet the requirements and have low ductility,which are prone to occurring flexural-shear even shear failure.The strengths of piers under E1 seismic effect basically meet the requirements,while the deformation capacity under E2 seismic effect need to be improved.The proposed method enables the identification of the bridge structures with high seismic fragility and their weakness scientifically and quickly in the simplest way possible,which can serve the decision of seismic strengthening for existing highway bridges in seismic high-risk areas directly.
关键词
既有公路桥梁/梁式桥/抗震性能评价/落梁/桥墩延性/地震易损性
Key words
existing highway bridge/girder bridge/evaluation of seismic performance/deck falling/pier ductility/seismic fragility
维普
万方数据