It has long been observed that timber structures, which tend to have stiff components but ductile connections, perform comparatively well in earthquakes [1]. A lot of research and effort has gone into demonstrating that this property translates into mass timber buildings as well, since many regions with active mass timber industries are also earthquake prone. This is certainly true in the Pacific Northwest, a landscape molded by seismic activity and blanketed in forest.
Buildings encounter different kinds of external loads and forces while in service. Structures contain multiple systems that are designed to manage these external forces. Gravity systems support the weight of the building itself, while lateral force resisting systems handle sideways forces introduced by events like wind and, more to the point, earthquakes.
In the event of an earthquake, the seismic ground movements induce an unusual set of forces and added energy into affected buildings, and that energy needs to go somewhere. Buildings designed according to seismic safety standards have designated pathways to dissipate the energy while retaining the life-safety of people in and around the building as much as possible. If they did not, the energy might dissipate in ways that could be very harmful to the building’s occupants.
In order to ensure that a given structural system is up to the challenge, researchers and engineers use a variety of tools to assess a structures potential response to a seismic event.
Seismic performance testing is often completed at multiple scales, working from small-scale component tests up to full specimens. This way, detailed information about the individual performance of specific elements and connections can be gathered before getting into the complexity of how they work together. Structural testing laboratories can be set up to mimic the back-and-forth motion of an earthquake at a much slower speed, or they can apply pressure in one direction until something fails. Often, the researchers are just as interested in the questions of what failed first, and how, as they are in the amount of force it took.
As a structural testing facility, this type of work is often found in Emmerson. In fact, this summer Dr. Erica Fischer’s lab set up a series of seismic and service tests for the largest mass timber diaphragm assembly ever studied in this manner, measuring in at 70ft x 30ft – nearly the entirety of Emmerson’s sizable strong floor.
In order to get closer to the real experience of an earthquake, where structures must contend with fast, unpredictable ground movements, an even more specialized facility is required. Large shaking tables, with the capability to simulate earthquakes underneath full-scale structures, are fairly uncommon, but the data they provide are invaluable.
As mass timber has matured as a structural material, so too has it made its way into the structures put to the test by shake tables worldwide. At this point, there have been several building-scale seismic testing programs dedicated to mass timber structures, providing a growing body of evidence that mass timber can achieve strong seismic performance. A few of those programs are discussed below.
The SOFIE project, a multiphase research project conducted by IVALSA (the Trees and Timber Institute of Italy’s National Research Council) was among the first of its kind when it concluded in 2008 [2,3]. It included a variety of tests involving European spruce (Picea abies) CLT, using several shake tables in Japan. The first full-scale specimen was a 3-story CLT building tested on a mono-axial shake table. The second was a 7-story CLT structure designed according to Eurocode 8, tested on a multi-directional table [4].
The shake table testing programs simulated 10 major earthquakes, and through it all, no residual drift was observed in either building. There was some minor, repairable damage – particularly in the building connections – but the researchers confidently indicated that the results of these tests fully supported the use of mass timber in earthquake prone regions.
A Japanese National Research Project funded by Ministry of Land, Infrastructure, Transport and Tourism of Japan that started in 2011, tested a series of panelized structures made from sugi (Cryptomeria japonica) CLT [5]. The structures, which ranged from 3 to 5 stories, featured panel systems of different orientations, aspect ratios, and connections. The tests were considered successful, with minimal drift and repairable damage, though one test did see a panel rupture in compression.
On the other side of the Pacific Ring of Fire, in 2017, some of the largest seismic testing programs for mass timber structures began. The NHERI TallWood project was a highly collaborative effort led by faculty from the Colorado School of Mines. Its opening effort involved subjecting a two-story mass timber building, outfitted with three different mass timber lateral systems over the course of the tests, to more than 30 separate ground motions and simulations of historically recorded earthquakes [6,7]. This test was a proof of concept for timber post-tensioned rocking walls as a seismically resilient lateral force resisting system in an open concept building [6–10].
Data from this study were used to inform another study of a 2-story mass timber building supported by FEMA, which provided data used to add CLT shear walls to the U.S. building code ASCE 7-22 [11–13]. It was also an early test of the timber post-tensioned rocking walls system that would later be utilized in Peavy Hall at OSU [10].
This series of tests was not the end, though. Researchers at OSU and beyond have continued to build out our understanding of the capabilities of mass timber construction, including the role it can play in resilient structures – those that can not only withstand an earthquake, but also recover from them.
[1] R. Langenbach, Resisting Earth’s Forces: Typologies of Timber Buildings in History, Structural Engineering International 18 (2008) 137–140. https://doi.org/10.2749/101686608784218806.
[2] A. Ceccotti, C. Sandhaas, M. Yasumura, Seismic performance of X-Lam buildings: the Italian SOFIE project, in: Proceedings of the 9th U.S. National and 10th Canadian Conference on Earthquake Engineering, EERI, Toronto, Canada, 2010: p. 10.
[3] A. Ceccotti, C. Sandhaas, M. Okabe, M. Yasumura, C. Minowa, N. Kawai, SOFIE project – 3D shaking table test on a seven‐storey full‐scale cross‐laminated timber building, Earthq Engng Struct Dyn 42 (2013) 2003–2021. https://doi.org/10.1002/eqe.2309.
[4] R. Nishi, Y. Kawamata, R. Enokida, T. Inoue, K. Tabata, E-Defense Shake Table Experiments Implemented by NIED and Collaborative Research Projects in 2005–2022, JDR 18 (2023) 492–512. https://doi.org/10.20965/jdr.2023.p0492.
[5] M. Sato, H. Isoda, Y. Araki, T. Nakagawa, N. Kawai, T. Miyake, A seismic behavior and numerical model of narrow paneled cross-laminated timber building, Engineering Structures 179 (2019) 9–22. https://doi.org/10.1016/j.engstruct.2018.09.054.
[6] J.W. van De Lindt, J. Furley, M.O. Amini, S. Pei, G. Tamagnone, A.R. Barbosa, D. Rammer, P. Line, M. Fragiacomo, M. Popovski, Experimental seismic behavior of a two-story CLT platform building, Engineering Structures 183 (2019) 408–422. https://doi.org/10.1016/j.engstruct.2018.12.079.
[7] A.R. Barbosa, L.G. Rodrigues, A. Sinha, C. Higgins, R.B. Zimmerman, S. Breneman, S. Pei, J.W. Van De Lindt, J. Berman, E. McDonnell, Shake-Table Experimental Testing and Performance of Topped and Untopped Cross-Laminated Timber Diaphragms, J. Struct. Eng. 147 (2021) 04021011. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002914.
[8] H.-E. Blomgren, S. Pei, Z. Jin, J. Powers, J.D. Dolan, J.W. Van De Lindt, A.R. Barbosa, D. Huang, Full-Scale Shake Table Testing of Cross-Laminated Timber Rocking Shear Walls with Replaceable Components, J. Struct. Eng. 145 (2019) 04019115. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002388.
[9] H.-E. Blomgren, S. Pei, Z. Jin, J. Powers, J.D. Dolan, J.W. Van De Lindt, A.R. Barbosa, D. Huang, Full-Scale Shake Table Testing of Cross-Laminated Timber Rocking Shear Walls with Replaceable Components, J. Struct. Eng. 145 (2019) 04019115. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002388.
[10] S. Pei, J.W. Van De Lindt, A.R. Barbosa, J.W. Berman, E. McDonnell, J. Daniel Dolan, H.-E. Blomgren, R.B. Zimmerman, D. Huang, S. Wichman, Experimental Seismic Response of a Resilient 2-Story Mass-Timber Building with Post-Tensioned Rocking Walls, J. Struct. Eng. 145 (2019) 04019120. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002382.
[11] J.W. Van De Lindt, J. Furley, M.O. Amini, S. Pei, G. Tamagnone, A.R. Barbosa, D. Rammer, P. Line, M. Fragiacomo, M. Popovski, Experimental seismic behavior of a two-story CLT platform building, Engineering Structures 183 (2019) 408–422. https://doi.org/10.1016/j.engstruct.2018.12.079.
[12] J.W. van de Lindt, M.O. Amini, D. Rammer, P. Line, S. Pei, M. Popovski, Seismic Performance Factors for Cross-Laminated Timber Shear Wall Systems in the United States, Journal of Structural Engineering 146 (2020) 04020172. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002718.
[13] S. Pei, K.L. Ryan, J.W. Berman, J.W. van de Lindt, S. Pryor, D. Huang, S. Wichman, A. Busch, W. Roser, S.L. Wynn, Y. Ji, T. Hutchinson, S. Sorosh, R.B. Zimmerman, J. Dolan, Shake-Table Testing of a Full-Scale 10-Story Resilient Mass Timber Building, Journal of Structural Engineering 150 (2024) 04024183. https://doi.org/10.1061/JSENDH.STENG-13752.
Degenkolb's structural engineering practice reflects more than eight decades of commitment to technical expertise, exceptional client service through close collaboration, and life-long learning. Degenkolb pioneers innovative structural system designs to support the needs of our clients, including mass timber projects as engineer-of-record, peer reviewer, and in construction engineering.
DLR Group is an integrated design firm delivering architecture, engineering, interiors, planning, and building optimization for new construction, renovation, and adaptive reuse. Our promise is to elevate the human experience through design. This promise inspires sustainable design for a diverse group of public and private sector clients; local communities; and our planet. DLR Group is 100 percent employee-owned and fully supports the initiatives and goals of the 2030 Challenge, and is an initial signatory to the China Accord and the AIA 2030 Commitment.
FFA has recently created 20 projects utilizing mass timber. For our team this is a design and research opportunity, leveraging post-occupancy evaluation, performance tracking, and material sourcing studies to continuously refine its approach. The dedication to using high-tech wood products for small and large projects helps us connect to our region through a range of attributes from aesthetics to economic solutions. This endeavor brings together multiple experts from across the research, design, and construction industry together creating better solutions for the community we serve.
Forell | Elsesser (F|E) is an award-winning structural engineering firm known for innovative design solutions that are practical and scalable. The firm brings deep expertise in mass timber design, with particular strength in vibration mitigation and performance-based seismic engineering for complex buildings. An active collaborator with academic partners and industry stakeholders, F|E contributes targeted research insights that help close knowledge gaps and support broader adoption of mass timber solutions.
Holmes is an international engineering firm specializing in advanced structural and fire engineering across the Pacific Rim. With deep expertise spanning research, design, and construction, Holmes has contributed to industry-advancing initiatives including collaborative research with academia, development of industry design guides and participation on multiple code advancement committees. This expertise extents particularly to mass timber, where Holmes has been involved in some of the largest and most innovative mass timber buildings in North America, New Zealand, Australia and beyond.
Kalesnikoff Mass Timber is a vertically integrated manufacturer specializing in mass timber (CLT, GLT, Glulam), prefabricated wall systems and fully volumetric modular construction. Through in-house R&D and advanced manufacturing, we optimize structural systems and detailing to improve constructability, performance, and code compliance across a wide range of building types.
KPFF is a nationally recognized structural and civil engineering firm with over 1,500 employees. We have contributed to the U.S. mass timber movement since its infancy in the Pacific Northwest and have helped expand its reach across the entire United States. We are especially passionate about translating mass timber research into practice including point-supported cross-laminated timber (CLT), post-tensioned timber rocking walls, mass timber floor vibration, CLT diaphragms, timber braced frames, fire and acoustic testing, large-scale shake-table testing, and many other research and development topics.
LEVER is a leading architectural practice based in Portland, Oregon and Los Angeles recognized for design excellence that combines purpose, craft and material innovation LEVER has pioneered mass timber firsts for over a decade, with projects that are catalysts for connecting sustainable urban development to rural economic growth regionally and nationally. The company’s office, Albina Yard, was the first building in the United States to use domestically sourced CLT and their Framework project was the first wood high-rise design in the United States to receive approval for construction. LEVER has designed over 20 mass timber projects focusing on leveraging the specific qualities of a place—climate, access to materials, community, and the resources of the specific sites of their work.
Mithun is a 75-year-old design firm with offices in Seattle, San Francisco and Los Angeles. The firm’s interdisciplinary team has been working with mass timber since 2017 on diverse projects spanning commercial office, cultural, industrial and education markets. As part of the Mithun R+D program, the firm has advanced mass timber knowledge and application through self-funded research like the Building Better Schools mass timber kit of parts system that has informed multiple K-12 projects at Mithun and been widely referenced by other institutions and firms in their efforts to design economical mass timber schools. Mithun also actively participates in industry-led research such as its successful execution of two NFPA 285 fire tests on CLT walls through the USDA Wood Innovations Grant program, acoustic testing in multifamily CLT floor assemblies, and a current research project with WSU and NRRI to develop a thermally modified strand-based CLT panel for commercial use.
Rothoblaas delivers practical, high-performance solutions for mass timber and wood construction, from structural fasteners and connection systems to membranes and safety products. Supported by internal testing, technical documentation, and engineering resources, Rothoblaas helps architects, engineers, and builders navigate U.S. code requirements with strong technical support and R&D driven guidance. Through education and collaboration, we help move mass timber projects from design to jobsite with confidence.
Degenkolb's structural engineering practice reflects more than eight decades of commitment to technical expertise, exceptional client service through close collaboration, and life-long learning. Degenkolb pioneers innovative structural system designs to support the needs of our clients, including mass timber projects as engineer-of-record, peer reviewer, and in construction engineering.
StructureCraft is an industry leader in the design, engineering, and fabrication of advanced mass timber and hybrid timber systems, with a strong focus on innovation and constructability. The company has extensive experience delivering complex timber structures globally. With deep expertise in digital fabrication and in-house R&D, StructureCraft collaborates closely with architects and researchers to push the boundaries of sustainable, low-carbon construction, bringing unique technical strength and practical insight to the REACTS group.
WSP is one of the world’s leading professional services firms, uniting engineering, advisory, and science-based expertise to shape communities. Within this global network, our structural engineering teams are recognized for innovative approaches to complex building systems. We apply advanced design strategies for mass timber and hybrid structures, combining sustainability with technical precision. Through ongoing research and development, we create resilient, future-ready solutions that redefine what’s possible in the built environment.
Freres Engineered Wood is a premier wood products manufacturing company dedicated to bringing innovative, high-quality and environmentally-sound wood products to market. Founded in 1922, Freres is one of the oldest family-owned and operated businesses in Oregon, and values the personal relationships it has developed with customers and partners over the years.
