Evaluating the Seismic Vulnerability of the BART Tunnels that Cross the Hayward Fault

Research Team: Jonathan P. Stewart, Yousef Bozorgnia, Esra Zengin, and Kenichi Soga

UC Campus(es): UC Berkeley, UCLA

Problem Statement: 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.

Project Description: This project aims to utilize the latest data and models to estimate the likelihood of fault rupture displacement and calculate the probability of BART system disruption in the event of a Hayward Fault earthquake. The researchers will use the Fault Displacement Hazard Initiative (FDHI) models previously developed by the UCLA Natural Hazards Risk and Resiliency Research Center (NHR3) to calculate fault displacement values for various rupture scenarios of the Hayward Fault. Then, they will develop probabilistic fault displacement hazard curves specifically for the Oakland-Orinda section of BART (which spans the Hayward Fault) and create a finite element computer model of the BART tunnels. This model will be essential for conducting simulations to predict how the tunnels will respond to different levels of fault displacement. Combining the hazard curves, the finite element model, and data from BART about the tunnels, the team will determine the probabilities of the rail system within the tunnels experiencing minor damage, dysfunctionality, or major damage.

Status: In Progress

Budget: $120,000