Probabilistic Functionality Loss Rate Model of Bridge Network for Regional Seismic Fragility Analysis

The evaluation of traffic functionality of bridge networks in post-earthquake is essential for rescue and reconstruction. The previous studies have a limitation of combination with individual bridge seismic performance analysis and network traffic functionality analysis, which brings a great difficulty to rational aseismic decision making at network-level. Therefore, a probabilistic functionality loss rate model (PFLRM) is established for bridge network. For estimating the network functionality loss, a novel index is defined in PFLRM, named functionality loss rate (FLR). Moreover, the assessment method of FLR is also provided accounting for seismic intensity measure (IM), individual bridge parameters and network topology. In addition, for improving the obtaining efficiency of FLR, a quantified model between FLR and IM is established, which has the advantages of applicability, accuracy and efficiency. The precision of proposed PFLRM is compared by Monte Carlo method on twelve benchmark networks. Finally, the proposed model can be applied on a real network for regional seismic fragility analysis to identify important bridges and make repair strategy.