Post-earthquake urban bridge traffic capacity loss assessment considering effects of structural component damage

Abstract:

As key components in urban transportation network, bridges play crucial roles in post-earthquake relief and reconstruction efforts. However, existing studies on post-earthquake losses of urban bridges primarily concentrate on repair costs for structural damage, paying less attention to the loss of vehicular traffic capacity, which makes it difficult to provide effective guidance for post-earthquake emergency responses and bridge rehabilitation decisions. Therefore, in this paper a method was proposed to assess the loss of post-earthquake traffic capacity of a bridge by comprehensively considering the seismic damage to bridge components and its impact on vehicular traffic. Firstly, in order to accurately analyze the effect of the earthquake on the bridge structure system, a seismic fragility analysis of the bridge system was conducted using the copula function, considering the interdependence of damage to bridge components. Secondly, an evaluation method was proposed for estimating the loss of traffic capacity in bridges due to earthquakes. Finally, the proposed method for assessing post-earthquake vehicular traffic capacity loss of urban bridges was tested through an example of a 4-span continuous girder bridge, which proves that it is more accurate and has less dispersion and uncertainty compared to existing assessment methods. Compared to traditional qualitative and subjective postearthquake functionality assessment of the damaged bridge, the proposed analytical approach considers the specific impact of seismic damage to bridge components on the traffic capacity of the bridge from a physical perspective, and offers a mathematical model for the decision-making process.