To enable resilient, eight to fourteen story, timber buildings in regions of high seismicity in the United States, this planning grant combines innovative concepts in seismic load resisting systems with a new form of a mass timber structural component, called cross laminated timber (CLT), to research three potential structural systems for resilient, tall CLT building construction: (a) single-story, pre-stressed re-centering walls, (b) multi-story, segmental rocking walls, and (c) deformable floor diaphragms with supplemental damping devices. These systems will be distributed vertically along the height of the building, combining deformable panels or layers with relatively rigid and stiff ones, to leverage CLT behavior, enable rapid construction, and limit the impact of higher modes. Based on their performance in component-level testing and system-level simulation conducted as part of this research, promising systems that are economically competitive will be selected for full-scale experimental investigation in follow-on research. This planning phase research will generate fundamental knowledge on resilient, multi-story panelized systems that have the potential to transform the seismic design of taller buildings in general.
As urban densification occurs in U.S. regions of high seismicity, there is a natural demand for tall buildings that can survive large earthquakes with minimal damage and interruption. CLT is a naturally sustainable material that has been used in Europe and Australia to rapidly construct multi-story buildings. However, existing multi-story CLT constructions were limited to regions of low seismicity because there is no seismic design methodology for tall CLT buildings worldwide. In the U.S. Pacific Northwest, there is significant interest in utilizing CLT in eight to fourteen story residential and commercial buildings due to its appeal as a potential locally sourced, sustainable, and economically competitive building material. With combined expertise from the research and design community, this project will address this societal need by prototyping three potential structural systems that are suitable for tall CLT buildings in high seismicity regions, comparing their performance through experimentation and simulation, and developing performance-based seismic design methods for their implementation. Once the optimal systems are selected in this study and verified at full-scale in subsequent research, it is envisioned that a resilient, tall CLT building will become an option for west coast cities in about six to eight years. In addition to providing research training for students working on the project, the project will deliver educational resources to introduce this new sustainable building type to students, stakeholders, and the general public. Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).
