MRI: Acquisition of Equipment to Simulate Collapse of Engineered Systems under Extreme Loads

University Of Washington, Seattle WA

Investigators

Abstract

Traditional structural and geotechnical systems have been engineered for gravity and wind loads. More recent technical advances have permitted more sophisticated engineering models to be developed to aid in engineering these systems to resist earthquake loading. Recent history has demonstrated that extreme loading events, such earthquakes, blast, and hurricanes, pose severe threats to the nation's infrastructure and economy. Engineering for extreme hazards presents several challenges to engineers, most importantly preventing loss of life caused by structural collapse. However, engineering models for design and analysis of structural and geotechnical systems are lacking, primarily a result of limitations of the experimental testing equipment upon which engineering models are based or validated. Acquisition of equipment to meet this testing need is critical, because the risk of progressive collapse is more prominent today than it has been historically. The UW Department of Civil and Environmental Engineering and the proposed research team have the facilities, expertise, and reputation to manage, calibrate and validate the proposed equipment, conduct the related research, attract new users and funding agencies. The equipment includes enhancement of the large testing machine (2.4 million pound capacity) to enable the application of large vertical loads to simulate demands resulting from collapse of part of a structure. In addition, instrumentation including laser-based and photogrammetic systems that use targets placed on the test specimens will permit the researchers to fully monitor the response of the specimens through collapse. The integration of this equipment and the existing equipment within the UW structural research laboratory will enable the desired simulation capabilities. For example, the 130 Liberty Plaza building in New York City was struck with a large piece of the framing of the collapsing World Trade Center Tower 2 on September 11, 2001, which caused the loss of 26 stories. Using this facility, the large testing machine would apply a varying gravity (vertical) load to a critical portion of the structure. Because the proposed test facility is more than 6.7 m (22 ft) tall, it could accommodate a full-scale specimen which is critical to simulating brittle response of structures. The test results would be valuable in that they could quantify demands on connections and undamaged members and establish the general collapse resistance of the system, including the effects of slabs and nonstructural elements. This unique testing capability would allow investigations into structural behavior that are not possible today, and funding for such work will be available from a wide range of sources. Similar tests could be performed on a wide range of structural systems such as braced frames, core walls, and moment frames, since these behaviors are not well understood. The proposed equipment will enhance the research and learning environments, improve and expand the research capabilities of the structural and geotechnical engineering groups within the UW Department of Civil and Environmental Engineering, and intensify the links to local and national funding agencies, research partners, and practicing engineers. The equipment will enhance classroom and laboratory learning at the undergraduate and graduate levels. In addition, the award-winning role of the structural research laboratory in community outreach will continue and broaden with this acquisition