Regional Risk Assessment of Underground Metro Infrastructure under Different Dynamic Loads
Underground metro infrastructures are subjected to different types of dynamic loads that would hinder their ability to function properly. This proposed research aims to assess the risks of city-scale underground tunnel networks under both periodic human-induced vibrations (i.e., blasting and drilling vibrations) and short-term extreme earthquake hazards. We will develop a GIS model for the tunnel soil/rock profiles in Montreal by synthesizing a comprehensive dataset for tunnel designs, embedment depths, and soil/rock properties from geotechnical surveys. Using the GIS data, we will develop high-fidelity three-dimensional (3D) finite element (FE) models to examine the dynamic behaviors of tunnels with interface conditions, namely segment joints where tunnel designs change and/or soil/rock profiles vary discontinuously. We will focus on examining to what degree the interface boundary would respond differently than other locations. Subsequently, we will expand the analyses to two-dimensional (2D) probabilistic FE analyses on the city-scale tunnel-soil/rock portfolios to evaluate the time-history responses of tunnels under varying levels of above-mentioned dynamic loads. The associated response demands will be convolved with stress limits and loading models to assess the regional risks of tunnel lines. Finally, we will incorporate the associated risk outputs into the GIS model to facilitate data visualization and risk interpretation.