Bridge seismic design method incorporating seismic importance adjustment factor and uniform traffic loss risk

Abstract

To assess the importance of bridges in road networks and achieve uniform traffic loss risk in seismic design, this paper introduces a novel bridge seismic design methodology incorporating the Seismic Importance Adjustment Factor (SIAF) and uniform traffic loss risk. The key technical contributions are as follows: (1) defining SIAF and developing an integrated framework that couples seismic design with traffic loss risk assessment; (2) proposing a calculation method for traffic loss risk that accounts for traffic demand variations during different periods of the day, uncertainties in post-earthquake bridge repair times, and dynamic traffic flow reassignment in post-earthquake road networks; (3) establishing design indicators for traffic loss risk and defining five seismic risk design levels based on historical disaster data; (4) validating the methodology through case studies on bridges and road networks, demonstrating how SIAF interconnects seismic design with risk-based design targets and adapt seismic design standards to varying network redundancies. The research demonstrates that SIAF can quantify bridge importance within complex road networks and provide a practical reference for the development of seismic design standards.