Tall Mass Timber Buildings in High Seismic Zones

Professor, Department of Civil and Environmental Engineering, University of Washington in Seattle

Mass timber construction offers benefits such as fast construction, architectural appeal and improved sustainability/reduced carbon footprint relative to conventional construction. With these benefits has come a growing interest in using mass timber structural systems for taller buildings (6-20 stories) that serve as urban infill in cities across the country. On the West Coast of the US, in particular, the interest in tall mass timber buildings is high and development of the necessary technologies are being supported by industry advocates as well as state and federal programs. For implementation of mass timber buildings in the high seismic zones of the Western US it is desirable to have mass timber lateral force resisting systems, although there are currently none that are recognized in building codes. This seminar will describe a comprehensive research program to bring forward post-tensioned mass timber rocking shear walls as a suitable lateral force resisting system for tall mass timber buildings. The presentation will cover the design methods, nonlinear modeling strategies, and experiments that led to the recent design, analysis, and successful testing of a full-scale 10-story mass timber building utilizing posttensioned mass timber shear walls on the NHERI large high performance outdoor shake table at the University of California San Diego. The 10-story building, designed for an urban neighborhood in Seattle, is the tallest structure ever tested on a shake table and was subjected to ground motions consistent with Seattle’s complex seismic hazard, including subduction zone and crustal fault hazards. The building was subjected to nearly 100 individual ground motions, many including 3D components, representing frequent to rare seismic hazard levels, including several runs with ground motions at the maximum considered earthquake hazard level. The building performed very well, meeting and exceeding performance and resilience targets. The research to be presented is part of the NHERI TallWood research program supported by the National Science Foundation, US Forest Service, Simpson Strong-Tie, and several other partners and is a collaboration between multiple universities.

Jeffrey Berman is a Professor in the Department of Civil and Environmental Engineering at the University of Washington in Seattle. He joined UW in 2006 after completing his BS, MS, and PhD at the State University of New York at Buffalo. He has worked on numerous large-scale destructive experimental investigations involving steel and heavy timber structures and sub assemblages. His research strives to blend experimental and numerical investigations to help develop the tools and understanding necessary for practicing engineers to design structures to resist the forces of earthquakes, blasts, and other hazards. He was the structural engineering lead on the M9 Project, a large NSF supported interdisciplinary research project investigating the impacts of magnitude 9 Cascadia Subduction Zone earthquakes on the Pacific Northwest. He is the Site Operations Director of the NSF supported NHERI Rapid Facility, a shared use equipment site supporting natural hazards reconnaissance headquartered at the UW and has served as the Director of the Large-Scale Structural Engineering Testing Laboratory. He serves on several national committees related to earthquake engineering and is active in various building code committees. Prof. Berman is also a dedicated instructor and is a past recipient of the UW Distinguished Teaching Award.