Live Load Distribution Factors for Spread Slab Beam Bridges
Publication: Journal of Bridge Engineering
Volume 22, Issue 10
Abstract
The design and construction of spread slab beam bridges is becoming commonplace in Texas. Although this relatively new class of bridge is somewhat similar to spread box beam bridges, it is unclear whether the existing live load distribution factor (LLDF) equations for the latter system are applicable for the former. Therefore, this paper presents the evaluation and derivation of flexural and shear LLDFs for the new spread slab beam bridge class. Thirty-one variations of these models were used to investigate an array of possible bridge geometries, and shear and moment LLDFs were derived for the design of spread slab beam bridges. Twenty-eight additional geometries were explored to derive correction factors for skew angle, overhang, and vehicle position. Existing AASHTO spread box beam bridge LLDFs range from being unconservative to very conservative when applied to spread slab beam bridges. Therefore, new LLDF expressions are developed to provide an appropriate estimate of load sharing for spread slab beam design in terms of moment and shear.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was supported by TxDOT and the Federal Highway Administration as part of TxDOT Project 0-6722. The authors are grateful to the TxDOT project monitoring committee and personnel who provided invaluable assistance. The support of the Texas A&M Transportation Institute is also greatly appreciated.
References
AASHO (American Association of State Highway Officials). (1931). Standard specifications for highway bridges, 1st Ed., Washington, DC.
AASHTO. (1994). AASHTO LRFD bridge design specifications, 1st Ed., Washington, DC.
AASHTO. (2002). Standard specifications for highway bridges, 17th Ed, Washington, DC.
AASHTO. (2014). AASHTO LRFD bridge design specifications, Washington, DC.
Abaqus 6.14 [Computer software]. Providence, RI, Dassault Systemes, SIMULIA.
CSiBridge [Computer software]. Berkeley, CA, Computers and Structures, Inc.
Eom, J., and Nowak, A. (2001). “Live load distribution for steel girder bridges.” J. Bridge Eng., 489–497.
Hays, C. O., Sessions, L. M., and Berry, A. (1986). “Further studies on lateral load distribution using finite element method.” Transportation Research Record 1072, 6–14.
Hueste, M. D., Mander, J. B., Terzioglu, T., Jiang, D., and Petersen-Gauthier, J. (2015). “Spread prestressed concrete slab beam bridges.” Research Rep. No. FHWA/TX-15/0 6722-1, Texas A&M Transportation Institute and Texas DOT, College Station, TX.
Huo, X., Conner, S., and Iqbal, R. (2003). “Re-examination of the simplified method (Henry’s method) of distribution factors for live load moment and shear.” Final Rep., Tennessee DOT Project No. TNSPR-RES, Tennessee DOT, Nashville, TN, 1218.
Jiang, D., Terzioglu, T., Hueste, M. D., Mander, J. B., and Fry, G. T. (2016). “Experimental study of an in-service spread slab beam bridge.” Eng. Struct., 127, 525–535.
Marx, H. J., Khachaturian, N., and Gamble, W. L. (1986). Development of design criteria for simply supporter skew slab-and-girder bridges, Illinois DOT, Univ. of Illinois at Urbana-Champaign, Urbana, IL.
Newmark, N. M. (1938). A distribution procedure for analysis of slabs continuous over flexible beams, Univ. of Illinois, Urbana, IL.
Puckett, J., Huo, S., Jablin, M., and Mertz, D. (2011). “Framework for simplified live load distribution-factor computations.” J. Bridge Eng., 777–791.
Sanders, W. W., and Elleby, H. A. (1970). “Distribution of wheel loads on highway bridges.” NCHRP Rep. No. 83, Highway Research Board, Washington, DC.
Terzioglu, T. (2015). “Behavior and design of spread prestressed concrete slab beam bridges.” Ph.D. dissertation, Texas A&M Univ., College Station, TX.
Terzioglu, T., Jiang, D., Hueste, M., Mander, J., and Fry, G. (2016). “Experimental investigation of a full-scale spread slab beam bridge.” J. Bridge Eng., 04016082.
Westergaard, H. M. (1930). “Computation of stresses in bridge slabs due to wheel loads.” Public Roads, 11(1), 1–23.
Zokaie, T., Imbsen, R. A., and Osterkamp, T. A. (1991). “Distribution of wheel loads on highway bridges.” NCHRP Project Rep. 12-26, Transportation Research Board, Washington, DC.
Information & Authors
Information
Published In
Copyright
© 2017 American Society of Civil Engineers.
History
Received: Dec 16, 2016
Accepted: Apr 20, 2017
Published online: Jul 28, 2017
Published in print: Oct 1, 2017
Discussion open until: Dec 28, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.