Bent Connection Options for Curved and Skewed SMC Bridges in Low-to-Moderate Seismic Regions
Publication: Practice Periodical on Structural Design and Construction
Volume 22, Issue 4
Abstract
Simple-made-continuous (SMC) multispan concrete bridges are popular in low-to-moderate seismic regions, and sometimes horizontally curved and/or skewed configurations are needed to accommodate complex terrain. Typical SMC multispan bridges can adopt different connections between the intermediate bent cap and the continuous superstructure (bent connection). Compared to their straight counterparts, skewed and curved SMC bridges exhibit more complex seismic performance, making the design choice of using bent connections critical in low-to-moderate seismic regions. Nonlinear time-history seismic analyses using structural analysis and design software are carried out on 12 bridge models with four geometric configurations (i.e., straight, skewed, curved, and skewed and curved) and three bent connections (i.e., fixed, pinned, and roller). The skewed and curved bridge is found to exhibit a larger overall seismic response than the other bridges for most bent connections. Different bent connections affect the seismic response of a bridge by modifying the structural load path, which in turn changes the seismic load transmitted between the superstructure and the substructure. For straight, skewed-only, and curved-only bridges, pinned or roller bent connections are found to be more seismic-friendly than fixed bent connections in terms of their relatively smaller overall seismic demands, apart from abutments. For skewed and curved bridges, the situation becomes complex, and a fixed bent connection might be preferred in some instances.
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Acknowledgments
This study was partially supported by the U.S. Department of Transportation (through the Mountain Plains Consortium). The content of this paper reflects the views of the authors, who are responsible for the facts and the accuracy of the information presented. The Colorado Department of Transportation provided important information on the prototype bridge for the project. Thomas Wilson, a former graduate research assistant, helped in the initial stage of FEM model development.
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Published In
Practice Periodical on Structural Design and Construction
Volume 22 • Issue 4 • November 2017
Copyright
© 2017 American Society of Civil Engineers.
History
Received: Jun 17, 2016
Accepted: Mar 13, 2017
Published online: Jun 1, 2017
Published in print: Nov 1, 2017
Discussion open until: Nov 1, 2017
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