Response of BART’s Berkeley Hills tunnel to fault displacement and impact on system functionality

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 study evaluates the seismic resilience of BART’s Berkeley Hills Tunnel that passes through the Hayward Fault, which is a high-activity strike-slip fault. 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. Considering a probabilistic distribution of fault rupture displacements, we assess the resulting tunnel damage. We also evaluate the likelihood of service interruptions caused by potential Hayward Fault events. The results indicate that the tunnels may experience minor to significant damage depending on the amplitude of the fault displacement, which can lead to repair times ranging from a few weeks to over a year.