Fragility Analysis Of Long-span Concrete Filled Steel Tube Arch Bridge

Suspender fracture and deck collapse is the main diseases facing CFST arch bridge.From both the suspender faults and earthquakes angle large of span steel arch bridge ofconcrete vulnerability studies, based on the topological vulnerability and seismic fragilityanalysis theory, nonlinear pushover and incremental dynamic analysis methods ofvulnerability under different conditions and different seismic suspender fracture strength ofthe structure were analyzed and plotted the theoretical fragility curves based on the analysisresults, provide guidance for the design and construction of large-span steel arch bridge ofconcrete. The main contents are as follows:(1) Based on the major diseases of CFST arch bridge inductive analysis, structuralanalysis of the research status vulnerability analysis and fracture aspects of the suspender,large clear span steel arch bridge concrete vulnerability analysis needed to solve theproblem, the purpose of and significance.(2) The structure of the topological vulnerability analysis theory, the importance andsensitivity coefficient analysis, evaluation of structural failure path through the searchperformance analysis of the failure of the local suspender in case of concrete steel archbridge vulnerability assessment of feasible sex; structural seismic vulnerability analysisbased on theory, reliability theory and Pushover analysis of static structural fragility curvesto establish and build structural dynamic characteristics of fragility curves algorithm andapplication of occasions incremental dynamic analysis (IDA), Recommend the basicprinciples and methods of CFST arch bridge seismic vulnerability analysis.(3) Based on vulnerability analysis method is suitable for concrete filled steel archbridge, made of concrete steel arch bridge vulnerability analysis process, the use ofpushover analysis method suspender rupture ductility of the role and impact of the bridgedeck, a special study, to determine the relative displacement between the adjacent suspenderbeam bridge deck as damage indicators and clear the deck ductility criterion states indifferent types of damage. (4) The method according to topological vulnerability analysis, the use ofsemi-dynamic approach to consider the impact of the role of the suspender, in the role ofconsidering constant load, two load and fracture impact, through the engineering example incombination without breaking the suspender dynamic analysis is carried out to explore theeffects of different combinations of suspender break the bridge deck, and the deck-basedsuspender fragility fracture were evaluated.(5) For the engineering example, consider the use of non-linear fiber model bridgedeck material, select the appropriate seismic waves, nonlinear model for calculatingincremental dynamic analysis, by analyzing the results of the linear fit, application methodto establish the reliability of the bridge panel theoretical fragility curves, and the resultingfragility curves were compared.