Evaluating the Seismic Vulnerability and Resilience of BART’s Berkeley Hills Tunnel

Abstract

Critical nodes in transportation networks, such as major transit tunnels and interchange stations, are vital for maintaining system functionality following a disruptive event such as a large earthquake. This project focuses on evaluating the seismic resilience of BART’s Berkeley Hills Tunnel that intersects the Hayward Fault, one of California’s most active seismic zones. The Hayward Fault poses a significant risk, with the potential for a magnitude 7+ earthquake that could severely impact the tunnel, potentially disrupting BART service and affecting the broader transit network. This study employs the latest fault displacement hazard data and models to estimate the probability of fault rupture displacements and assesses the resulting damage. It then evaluates the likelihood of service interruptions caused by potential Hayward Fault events. Theresults suggest that the tunnels may experience minor to significant damage depending on the amplitude of the faultdisplacement, which can lead to repair times ranging from a few weeks to over a year. The findings highlight the importance of improving tunnel resilience to minimize service disruptions and ensure efficient recovery following major earthquakes.

About the Project

Certain critical points in transportation networks, like interchange stations and tunnels crossing active faults, significantly impact the flow of people and commerce in urban areas. Loss of capacity at such points impacts the population and economy of the region, and the speed with which repairs are made affects how well cities can recover after major earthquakes. The Hayward Fault – located in the San Francisco Bay Area – is one of California’s most active faults, with the potential to generate a major earthquake, magnitude 7 or higher. Such an earthquake can induce substantial ground displacement, potentially disrupting the tunnels and the BART system.