Earthquakes pose a severe threat to the nation's seaports, which are critical assets in this era of global trade. The seismic risk issues ports face are unique due to the nature of their infrastructure, long-range planning horizon, diversity of stakeholders, and the roles of port authorities. This Grand Challenge project integrates engineering, logistics, risk analysis, and decision sciences within a seismic risk reduction framework that uses the performance of the port system rather than its individual components as the basis for seismic risk mitigation decisions. This systems-level approach is essential for estimating the full scope of direct and indirect losses following an earthquake. The NEES program enables a novel, integrated experimental and numerical simulation approach to advance understanding of the complex soil-foundation-structure systems that are typical of ports to develop geotechnical and structural mitigation alternatives targeted at all parts of the soil-foundation-structure system. The research program examines two innovative soil improvement techniques that are well suited to port facilities and evaluates their performance using the NEES@UTexas mobile shaker and the NEES@UCDavis centrifuge. The strength and ductility of piles and their connections to the overlying deck play a vital role in the seismic performance of pile-supported wharves. Improved pile configurations and pile-deck connections will be developed using full-scale tests at NEES@UIUC. Emphasis will be placed on techniques that are "repair-friendly" and can quickly and inexpensively be returned to service following an earthquake. Tests will be performed at NEES@Buffalo to investigate innovative bracing systems to mitigate damage to cranes from large ground displacements due to liquefaction. These tests exploit the full potential of the NEES program by using hybrid numerical and experimental simulation. The experimental studies on these soil-foundation-structure systems will be used to develop and calibrate numerical models. An important contribution is the development of soil-pile and pile-deck dynamic macroelements that will fill the existing gap between simplified solutions and computationally intensive numerical solutions for soil-structure interaction problems. Numerical simulations will be used to develop fragility relationships for the integrated soil-foundation-structure system that lead directly to the operational capacity of the wharf following an earthquake and facilitate the subsequent determination of repair requirements for the damaged system. Fragility relationships will be developed that reflect the performance of treated soils, improved pile-deck connections, and retrofitted cranes so that the effects of these mitigation alternatives on the operational capacity and repair requirements can be discerned.
Understanding system-level impacts of risk mitigation strategies on the functionality of a port is a crucial component of the seismic risk reduction framework. Advanced meta-heuristics for real-time operations optimization given component disruptions will be developed to provide decision support to stakeholders. Parametric approximation models of port system performance measures that can be incorporated directly into an optimization-based risk mitigation framework to inform decision makers will also be developed. Application of formal research on stakeholder participation and behavioral decision making to risk mitigation at ports has been extremely limited to date. The nature of seismic risk in ports and port authorities and operations make them fertile ground for the social and decision sciences research proposed in this project. The project furthers value-focused decision research by integrating it with research on how stakeholders and experts perceive and understand seismic hazards and risks. In doing so, the project will provide new insights on the relative roles of mental models of risks, values, and institutional affiliations in judgment and decision making about seismic and other risks.
The broader impacts of this project include the application of the real-time decision support models to minimize the impact of an act of terrorism at a U.S. port. Ports are thought to be one of the most vulnerable components of the nation's transportation system. Like natural hazards, acts of terrorism reduce the throughput capacity of the port by damaging some or all of a port's facilities. In this respect, the development of these decision support models that optimize throughput capacity during periods of disruption can contribute to increased homeland security. The education, outreach, and training program promotes education at several levels and addresses the dearth of under-represented students in STEM (Science, Technology, Engineering, and Mathematics) fields. A collaborative HBCU-REU program will increase the number of under-represented students in the STEM areas that pursue advanced degrees; Minority Postdoctoral Fellowships will help bridge the link from graduate school to academia; and an Industrial Fellowship Program will aid in technology transfer to practicing engineers. These programs form a continuum from undergraduate through professional education and will make a significant impact on creating a diverse workforce in the STEM areas.
