Toward a performance-based earthquake engineering analysis of short-medium span steel-concrete composite bridges

In this paper, the preliminary results of a vulnerability analysis carried out on a case study, consisting of short-medium span steel-concrete composite I-girder bridges are presented and discussed. The selected case study is part of the a group of bridges analysed within the SEQBRI project, funded in 2012 by the European Union, that deals with a systematic development of the Performance-Based Earthquake Engineering (PBEE) for short-medium span steel-concrete composite I-girder bridges including seismic input randomness, demand and damage analysis as well as economic cost-benefit estimations. More in particular, the definition of proper EDPs (Engineering Demand Parameters) and DMs (Damage Measured) are investigated through a non-linear numerical model of the bridge, which is developed in OpenSEES environment and analysed using IDA technique. Fragility curves will be developed with the aim to better understand the correctness of the selected response and damage parameters for the evaluation of the seismic vulnerability of this kind of bridges.