Load and Resistance Factor Calibration For Wood Bridges
Publication: Journal of Bridge Engineering
Volume 10, Issue 6
Abstract
The paper presents the calibration procedure and background data for the development of design code provisions for wood bridges. The structural types considered include sawn lumber stringers, glued-laminated girders, and various wood deck types. Load and resistance parameters are treated as random variables, and therefore, the structural performance is measured in terms of the reliability index. The statistical parameters of dead load and live (traffic) load, are based on the results of previous studies. Material resistance is taken from the available test data, which includes consideration of the post-elastic response. The resistance of components and structural systems is based on the available experimental data and finite element analysis results. Statistical parameters of resistance are computed for deck and girder subsystems as well as individual components. The reliability analysis was performed for wood bridges designed according to the AASHTO Standard Specifications and a significant variation in reliability indices was observed. The recommended load and resistance factors are provided that result in consistent levels of reliability at the target levels.
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Acknowledgments
The presented research was partially sponsored by the USDA Forest Service, Forest Products Laboratory, and by the Federal Highway Administration as part of the ISTEA Timber Bridge Research Program, which are gratefully acknowledged. The writers thank Michael Ritter and Joseph Murphy for fruitful discussions and suggestions.
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Information & Authors
Information
Published In
Journal of Bridge Engineering
Volume 10 • Issue 6 • November 2005
Pages: 636 - 642
Copyright
© 2005 ASCE.
History
Received: Feb 9, 2004
Accepted: Jan 31, 2005
Published online: Nov 1, 2005
Published in print: Nov 2005
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