The Florida Atlantic University (FAU) student chapter of Women’s Transportation Seminar (WTS) and the Freight Mobility Research Institute (FMRI) hosted a Webinar titled “Resilience of Intermodal Transportation Infrastructure under Multiple Hazards” with Dr. Jamie E Padgett on March 3, 2021. Both organizations are housed in the FAU College of Engineering and Computer Science Department of Civil Environmental and Geomatics Engineering. The presentation centered on multi-hazard risk and resilience assessment frameworks for transportation infrastructure such as ports, highway and railway infrastructure exposed to earthquake and hurricane hazards. Resilience assessment of intermodal freight networks was emphasized leveraging case study examples that probe the potential for damage, impact of mitigation and cascading social or economic consequences.

Dr. Jamie Padgett is Chair and Professor in the Department of Civil and Environmental engineering at Rice University, Houston, Texas. Her research focuses on risk assessment of structures and infrastructure, and the subsequent quantification of resilience and sustainability in the face of multiple hazards. Dr. Padgett’s group develops methods to evaluate and mitigate the consequences of hazards such as hurricanes, earthquakes and flooding, some impacting individuals, others the infrastructure system, and others on a broad community and regional scale. Dr. Padgett has published over 250 journal articles/conference proceedings in the general area of structural response, reliability resilience and lifecycle development.  The following is a summary of her presentation; we encourage readers to view the complete presentation using the link at the bottom of this article.

In the seminar, Dr. Padgett highlighted the role of increasing hazard exposures and losses, referencing the National Oceanic and Atmospheric Administration 2019 Data showing a significant yearly rise in billion-dollar disaster events characterized by shifting of intensity of the hazard events or changes in the built of the environment. The National Academy of Science defines resilience as the ability to prepare and plan for absorption, recovery from and more successfully adapt to adverse events. The Intermodal Resilience Analysis Framework, she shared, characterizes the hazard model whether it is a single or multi-hazard event and the intensity measure of the event at key locations of the infrastructure assets. Input Fragility Models help assess the vulnerability of the built assets to these intensities measured by, for example, the potential for damage to highway network components to intermodal terminals or to railway network components such as bridges. The models are needed to estimate not only the immediate post-event functionality or usability of the assets but also the potential restoration of functionality based on repair activities and recovery efforts through time.

These models can be either coupled within a broader community resilience framework or used to look at different indices of resilience such as the temporal evolution of functionality or metrics. Hazard Models use hazard occurrence characterization and spatial hazard intensity modeling, Exposure Models provide information for spatially distributed structures such as location, structural type and replacement cost, and Fragility Models provide probability of exceeding a certain limit state for the structures given the hazard intensities through surrogate demand modeling, limit state capacity characterization and fragility curves/parameterized fragility function.

Some high-level projects undertaken by Dr Padgett’s team projects using Fragility Models include models of seismic loads to address current gaps in the literature placed on coastal transportation assets, and roadway Fragility Models considering storm effects like inundation duration from coastal surge etc. Restoration Models quantify temporal functionality and restoration of structure and systems and are informed by empirical and survey data. Some examples include generic restoration function comparing functionality or performance to the traffic carrying capacity of a bridge, decision trees to look at immediate functionality based on combinations of component damages and estimating time for removal of restrictions like load restrictions, lane or speed restrictions beyond looking at damage to individual assets.

Recovery scheduling employs network analysis to measure the heuristic or optimal deployment of repair and recovery resources across networks. The Seismic Resilience Modeling of the Rail-Truck Intermodal Transportation Networks from the Memphis Metropolitan Statistical Area (MMSA) leverages finding element models of our bridge structures when subjected to earthquake ground motions in order to estimate the response under a whole range of different intensity measures of the hazard event and characteristics of the structure using Latin hypercube sampling or seismic demand meta models or statistical predictions of bridge component responses like the bearing response or column response or abutment response.

The Integrated Multi-Scale Intermodal Network is optimized for regional or local areas of interest. Evaluation of Network Component Functionality is determined by the Monte Carlo Simulation of intermodal network with randomly assigned restoration and Initial loss of Network functionality dictated by intermodal terminals and long term loss of network functionality dictated by bridges. “One of the main intentions is to support different types of decision making allowing comparative assessment of different pre-event investments like retrofit or upgrade or supportive deployment of inspection or resources for repair and recovery.” Recovery is prioritized based on the importance of the component in the overall connectivity of the transportation network. Dr. Padgett ended the lecture by highlighting the importance of pursuing smart resilience with diverse, emerging data sources, sustainability assessment and situational awareness.

We invite you to view the full event here

About the Author:

Dr. Nikitha Kolapalli is a health economist/clinical pharmacist pursuing her masters in Healthcare Decision Analysis from the USC School of Pharmacy. She works as a staff writer and editor for the METRANS student team. She is deeply passionate about maximizing accessible, equitable and affordable healthcare.