This award is an outcome of the NSF 07-506 program solicitation George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR) competition and includes Utah State University as the lead institution with subawards to the University of California, Berkeley; University of Wisconsin, Green Bay; and the University at Buffalo. Recent earthquakes have shown that even moderate ground shaking can produce large economic losses and major societal disruptions due to the widespread structural, nonstructural, and contents damage in code compliant buildings. Seismic isolation, in conjunction with energy dissipation, offers a simple and direct opportunity to control or even eliminate damage by simultaneously reducing deformations and accelerations. The United States once led the development and application of seismic isolation, but now this technology is more widely used in other countries. This project conducts a strategic assessment of the economic, technical, and procedural barriers to the widespread adoption of seismic isolation in the United States. NEES resources will be used for experimental and numerical simulation, data mining, networking and collaboration to understand the complex interrelationship among the factors controlling the overall performance of an isolated structural system. Innovative conceptual solutions will be developed for reducing construction costs (e.g., more effective placement of isolators and improved architectural detailing) and improving performance of isolation systems (e.g., use of new isolation devices). Coordinated experiments and computations will address behavioral uncertainties related to isolation devices, such as thermal heating, buckling and tensile capacity, geometric scaling, and strain rate effects. This project will involve shaking table and hybrid tests at the NEES experimental facilities at the University of California, Berkeley, and the University at Buffalo, aimed at understanding ultimate performance limits to examine the propagation of local isolation failures (e.g., bumping against stops, bearing failures, uplift) to the system level response. These tests, including a full-scale, three-dimensional test of an isolated 5-story steel building on the E-Defense shake table in Miki, Hyogo, Japan, will help fill critical knowledge gaps, validate assumptions regarding behavior and modeling, and provide essential proof-of-concept evidence regarding the importance of isolation technology. This integrated, holistic approach to cost-effectively and reliably limit the adverse impacts of earthquakes is also supportive of emerging trends in construction towards sustainable design. This knowledge will be integrated into a rational performance-based procedure that allows consistent comparison of the performance of alternative isolation and conventional systems in terms of safety, loss of use, and life cycle costs.
The new knowledge, tools, and performance-based design framework will facilitate the effective application of seismic isolation technology, leading to substantial reductions in the losses and disruptive societal impacts associated with future earthquakes. Through a needs assessment survey and workshop series, decision makers, professional engineers, researchers from throughout the United States and Japan, and representatives from industry and regulatory bodies will share strategies, resources and technology, and synergistically foster application. Existing resources will be leveraged for activities to educate a national audience, ranging from K-12 to practitioners, about seismic isolation technology. The project will involve undergraduate students through the NEES REU and LSAMP programs, on-site experiments, and other research activities. Following the experiments, all data will be made available through the NEES data repository (www.nees.org).
