Structural Integrity of Bolted Glulam Frame Connections Reinforced with Self-Tapping Screws in a Column Removal Scenario
Publication: Journal of Structural Engineering
Volume 146, Issue 10
Abstract
An experimental study has been carried out to investigate the behavior of glulam beam-to-column bolted connections subjected to monotonic loading in a column removal scenario. Eight test groups, each including four replicates of a wood-steel-wood glulam bolted connection configuration, were experimentally examined. The connections in four test groups were reinforced perpendicular to wood grain with self-tapping screws (STS). Test results showed that in the event of a column removal, the connections behaved as semirigid connections with considerable moment-resisting capacity, unlike typical beam-to-column timber connections that are assumed to be perfectly pinned. Experimental results also revealed that increasing the number of bolt rows from two to three rows, with each row having two bolts, increased the moment-carrying capacity of both unreinforced and reinforced connections with increments greater than those obtained by increasing the bolt end distance from four to five times the bolt diameter. Most importantly, STS-reinforced glulam connections manifested considerably increased moment-carrying capacities compared to the respective unreinforced connections by a factor ranging between 1.30 and 2.4. This has proven the ability of such glulam frame connections to redistribute the applied load and successfully transfer it to adjacent structural elements in case of column removal that could be caused by fire, explosion, or accidental damage.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
This research project was funded using a NSERC-Discovery Grant awarded to the second author, as well as a partial in-kind contribution provided by Nordic Structures Inc. Any opinions, findings, conclusions, or recommendations are those of the authors and do not necessarily reflect the views of the sponsoring parties. The authors would like to thank B. Vasconcelos, C. Tomiuck, C. Hubbard, I. Grant, N. Lepoudre, and J. Kruse for their assistance in preparing a few of the test specimens and in conducting a number of this research project’s experiments. Special thanks go to Dr. M. Leitch from the Faculty of Natural Resources Management at Lakehead University for his kind assistance in preparing the slotted cuts in all glulam beam sections tested in this project using his portable band-saw mill, and to Conrad Hagstrom and Rob Timoon for their help in the Dept. of Civil Engineering’s Structures Laboratory.
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Published In
Journal of Structural Engineering
Volume 146 • Issue 10 • October 2020
Copyright
© 2020 American Society of Civil Engineers.
History
Received: Sep 3, 2019
Accepted: May 5, 2020
Published online: Jul 27, 2020
Published in print: Oct 1, 2020
Discussion open until: Dec 27, 2020
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