Analysis and Design of Straight and Skewed Slab Bridges
Publication: Journal of Bridge Engineering
Volume 17, Issue 2
Abstract
Results of an investigation aimed at determining bending moments and shear forces, required to design skewed concrete slab bridges using the equivalent-beam method are presented in this paper. Straight and skewed slab bridges were modeled using grillage and finite-element models to characterize their behavior under uniform and moving loads with the objective of determining the most appropriate modeling approach for design. A parametric study was carried out on 390 simply supported slabs with geometries covering one to four lane bridges of 3- to 20-m spans and with skew angles ranging from 0 to 60°. The analyses showed that nonorthogonal grillages satisfactorily predict the amplitude and the transverse distribution of longitudinal bending moments and shear forces, and can be used for the analysis of skewed slab bridges. Results of the parametric study indicated that shear forces and secondary bending moments increase with increasing skew angle while longitudinal bending moments diminish. Equations are proposed to include, as part of the equivalent-beam method for skew angles up to 60°, the increase of shear forces and the reduction of longitudinal bending moments. Equations are also given for computing secondary bending moments. A simplified approach aimed at determining the corner forces for straight and skewed bridges is proposed as an alternative to a more-refined analysis. The analyses indicated the presence of high vertical shear stresses in the vicinity of free edges that justifies suggesting to provide shear reinforcement along the slab free edges.
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Acknowledgments
The authors would like to acknowledge the financial support obtained from the Natural Sciences and Engineering Council of CanadaNSERC, the Quebec Ministry of Transportation, and the Consultants of Montreal, Canada.
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Information & Authors
Information
Published In
Journal of Bridge Engineering
Volume 17 • Issue 2 • March 2012
Pages: 289 - 301
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Apr 25, 2010
Accepted: Mar 24, 2011
Published online: Mar 26, 2011
Published in print: Mar 1, 2012
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