Description:

Development and Shake Table Testing of an Inertial Force-Limiting Floor Anchorage System for Low Damage Seismic Building Structures

ABSTRACT
A new floor connecting system is being developed for low-damage seismic-resistant building structures. The system, termed an Inertial Force-Limiting Floor Anchorage System (IFAS) is intended to limit the seismic forces in buildings during an earthquake. This objective is accomplished by providing low-strength deformable connections between the floor system and the primary elements of the lateral force resisting system. The connections transform the seismic demands from inertial forces to relative displacement of the floors, thereby dissipating the earthquake energy. This talk describes the development of the IFAS via a multi-university National Science Foundation (NSF) Network for Earthquake Engineering Simulation Research (NEESR) Project involving the University of Arizona, Lehigh University and University of California-San Diego. The project involved extensive analytical research to optimize the IFAS design properties, leading to the development of an IFAS prototype using state-of-the-art components. The project culminated with IFAS performance being demonstrated in a shake table testing program that provided a direct comparison with an equivalent traditional “rigidly-anchored floor” structure. The test structure was a half-scale four-story reinforced concrete flat plate shear wall structure. Precast hybrid rocking walls and special precast columns were used for test repeatability for a 22 strong motion sequence. The structure was purposely provided with an eccentric wall layout to examine the performance of the system in coupled translational-torsional response. The test results indicate a seismic demand reduction in the IFAS structure relative to the traditional structure, including lower shear wall base rotation, shear wall and structure inter-story drift, and accelerations. These results indicate the potential for the IFAS to minimize structural and non-structural damage during earthquakes.

BIOGRAPHY
Dr. Robert B. Fleischman is a Professor in the Department of Civil and Architectural Engineering & Mechanics at the University of Arizona (UA). He formerly held the Delbert R. Lewis Associate Professorship at UA. Dr. Fleischman received his B.S. from Carnegie-Mellon University and his M.S. and Ph.D. from Lehigh University. Dr. Fleischman has industry experience at Turner Construction (New York, NY), Thornton-Tomasetti/C-B-M (Chicago, IL) and Rutherford & Chekene (San Francisco, CA), and is a member of several national committees.
Dr. Fleischman’s research area is seismic resistant design of precast/prestressed concrete and steel structures with recent focus on the development of new low-damage seismic-resistant building systems and floor diaphragms and collectors. He has served as Principal Investigator (PI) on over $5M of external funded research, and has 80+ journal publications/conference papers. His research has integrated computational simulation with physical experiments, including over 30 large-scale structural tests and three large-scale shake table tests. The findings of one project, the development of a new design methodology for precast concrete floor diaphragms, has been included in the ASCE 7-16 Load Standards and Part 3 of the 2015 National Earthquake Hazards Reduction Program (NEHRP) Recommended Provisions for Seismic Design for New Buildings.
Dr. Fleischman has won several national awards for his research on precast floor systems including the 2016 American Society of Civil Engineers (ASCE) Charles Pankow Award for Innovation, the National Science Foundation (NSF) 2014 NEES Outstanding Contributor Award, and the Precast/Prestressed Concrete Institute (PCI) 2014 Leslie D. Martin Award of Merit, the 2009 and 2004 Martin P. Korn Awards, the 2006 Charles C. Zollman Award, and 2004 George D. Nasser Award. Dr. Fleischman has led earthquake reconnaissance teams to Haiti and New Zealand, and was recently named a 2018-19 U.S. Fulbright Global Scholar. Dr. Fleischman has also won teaching awards at the University of Arizona eight times in the past decade.