Information-dependent seismic reliability assessment of bridge networks based on a correlation model

The focus of this study is the seismic reliability assessment of bridge networks, which is normally recognised with temporal and spatial variations similar to other engineered systems. The essence of such variation is that the assessment actually changes with available information. The relevant ‘information’ is clarified here and simply divided into two categories, i.e. the basic properties of the network together with the hazards and the real performance of part of the network. Correspondingly, approaches to an assessment with different categories of information are identified, and the framework for an information-dependent seismic reliability assessment is formulated. The basis for such information-dependent assessment is the description of the dependence structure of the seismic performance of bridges. Here, a correlation model that covers different aspects relevant to bridge performance is derived to play such role and is combined with the fragility analysis of individual bridges to realise the network reliability assessment and the importance measure of components in the priority of information collection. The proposed framework, together with the correlation model, is demonstrated in an example of a traffic network that connects 8 cities by highways with 12 standard reinforced-concrete overpass bridges in California.