Fragility function for assessing seismic risk of typical concrete bridge by means of nonlinear static and dynamic analysis

Abstract

Bridge with concrete pier and deck is a conventional highway infrastructure built and utilized in Indonesia. More than half of these typical bridges have been in service more than 20 years. Evaluating these sort of bridge subject to various intensity of earthquake in its future service life is important. This assessment helps owner to predict damages and economic losses due to earthquake as well as to plan and devise seismic rehabilitation intervention prior to the event. The analysis uses fragility function describing the probability of exceedance of certain damage level due to single predictive demand parameter or earthquake intensity measure, i.e. spectral acceleration on bridge structure. The concrete bridge was modelled deterministically with 3-D computational structural model. Analytical non-linear static and non-linear dynamic pushover (incremental dynamic analysis) was employed to determine the structural response. Fragility function eventually is expressed as series of log normal curves which can be used to assess the seismic risk of the bridge considered.