Experimental Seismic Behavior of a Full-Scale Four-Story Soft-Story Wood-Frame Building with Retrofits. I: Building Design, Retrofit Methodology, and Numerical Validation
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VIEW THE REPLYPublication: Journal of Structural Engineering
Volume 142, Issue 4
Abstract
Soft-story wood-frame buildings have been recognized as a disaster preparedness problem for decades. There are tens of thousands of these multifamily three- and four-story structures throughout California and other parts of the United States. The majority were constructed between 1920 and 1970 and are prevalent in regions such as the San Francisco Bay Area in California. The NEES-Soft project was a five-university multiindustry effort that culminated in a series of full-scale soft-story wood-frame building tests to validate retrofit philosophies proposed by (1) Federal Emergency Management Agency’s recent soft-story seismic retrofit guideline for wood buildings and (2) a performance-based seismic retrofit (PBSR) approach developed as part of the NEES-Soft project. This paper is the first in a set of companion papers that presents the building design, retrofit objectives and designs, and full-scale shake table test results of a four-story () soft-story test building. Four different retrofit designs were developed and tested at full scale, each with specified performance objectives, which were typically not the same. Three of these retrofits were stiffness or strength–based strategies and one applied supplemental damping devices in a pinned preassembled frame. This paper focuses on the building and retrofit design methodologies and specifics and the companion paper presents the experimental results of full-scale shake table tests ranging from 0.2- to 1.8-g spectral acceleration for all four retrofits.
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Acknowledgments
This material is based on work supported by the National Science Foundation under Grant No. CMMI-1041631 and 1314957 (NEES Research) and NEES Operations. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the investigators and do not necessarily reflect the views of the National Science Foundation. A sincere thank you to Simpson Strong Tie for their financial, personnel, and product support throughout the project, including the engineering support for the SMF in San Diego. Cash, personnel, or in-kind contributions were provided by the USDA Forest Products Laboratory, Structural Engineers Association of Southern California, Taylor Devices, and Innovative Timber Solutions/Smartwood. The authors kindly acknowledge the other co-principal investigators (Co-PI’s) of the project, Weichiang Pang and Xiaoyun Shao, and other senior personnel of the NEES-Soft project: David V. Rosowsky at University of Vermont, Andre Filiatrault at University at Buffalo, Shiling Pei at South Dakota State University, David Mar at Tipping Mar, and Charles Chadwell at Cal-Poly San Luis Obispo; the other graduate students participating on the project: Ph.D. students Ershad Ziaei (Clemson University) and Jingjing Tian (Rensselaer Polytechnic Institute) and M.Sc. students Jason Au and Robert McDougal at Cal-Poly Pomona; and the practitioner advisory committee: Laurence Kornfield, Tom Van Dorpe, Doug Thompson, Kelly Cobeen, Janiele Maffei, Douglas Taylor, and Rose Grant. A special thank you to all of the research experience for undergraduate (REU) students: Sandra Gutierrez, Faith Silva, Gabriel Banuelos, Rocky Chen, and Connie Tsui. Others that have helped include Asif Iqbal, Andre Barbosa, Vaishak Gopi, Steve Yang, Ed Santos, Tim Ellis, Omar Amini, Russell Ek, Rakesh Gupta, and Anthonie Kramer. Finally, our sincere thank you to NEES and all site staff and site Principal Investigators (PI’s) at NEES at the University of California San Diego for their assistance in getting the test specimen ready for testing and in conducting the tests.
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Published In
Journal of Structural Engineering
Volume 142 • Issue 4 • April 2016
Copyright
© 2014 American Society of Civil Engineers.
History
Received: May 29, 2014
Accepted: Oct 24, 2014
Published online: Dec 9, 2014
Discussion open until: May 9, 2015
Published in print: Apr 1, 2016
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