Development of Bridge Column Longitudinal Reinforcement in Oversized Pile Shafts
Publication: Journal of Structural Engineering
Volume 142, Issue 11
Abstract
This paper presents an experimental investigation to determine the embedment length required for longitudinal reinforcement in a bridge column extending into an oversized pile shaft, and the amount of transverse reinforcement required for the pile shaft to prevent premature bar anchorage failure due to concrete splitting induced by bar slip. Four full-scale column–oversized pile assemblies were tested under quasi-static cyclic lateral loading. The test specimens had different embedment lengths for the column reinforcement, different amounts of transverse reinforcement in the piles, different sizes of longitudinal bars, ranging from No. 8 to No. 18 (25 to 57 mm) bars, and different column-to-pile diameter ratios. All column–pile assemblies behaved in a ductile manner with plastic deformation occurring near the base of the columns despite some cone-shaped fractures and tensile splitting cracks occurring in the top portion of the piles. The test results show that the embedment length for the column reinforcement can be significantly reduced as compared to that required in current design specifications. The study also shows that an engineered steel casing designed according to a formula proposed here can effectively confine the pile shaft and significantly reduce splitting cracks.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Funding for the research presented in this paper was provided by Caltrans under Contract No. 59A0710. The authors appreciate the technical input provided by Caltrans engineers throughout this study. However, the opinions expressed in this paper are those of the authors and do not necessarily reflect those of the sponsor. The experiments presented in this paper were conducted in the Charles Lee Powell Structural Engineering Laboratories at UC San Diego. The authors would like to express their gratitude to the laboratory staff for their professionalism and high-quality technical support. The authors would also like to thank Mr. Charles Cummings, a former UC San Diego undergraduate student, for his assistance in the preparation of the column–pile assembly tests.
References
AASHTO. (2010). LRFD bridge design specifications, 5th Ed., Washington, DC.
AASHTO. (2011). AASHTO LRFD seismic bridge design specifications, 2nd Ed., Washington, DC.
AASHTO. (2012). LRFD bridge design specifications, 6th Ed., Washington, DC.
ACI (American Concrete Institute). (2001). “Control of cracking of concrete structure.” ACI 224R-01, Farmington Hills, MI.
ASTM. (2009). “Standard specification for low-alloy steel deformed and plain bars for concrete reinforcement.” ASTM A706/A706M-09b, West Conshohocken, PA.
Cairns, J., and Jones, K. (1996). “An evaluation of the bond-splitting action of ribbed bars.” ACI Mater. J., 93(1), 10–19.
Caltrans (California Department of Transportation). (2008). “Bridge design specifications.” Sacramento, CA.
Caltrans (California Department of Transportation). (2013). “Caltrans seismic design criteria, version 1.7.” Sacramento, CA.
Liu, Y. (2012). “Lateral behavior of reinforced concrete columns supported on type II shafts.” M.S. thesis, Dept. of Structural Engineering, Univ. of California, San Diego.
Lukose, K., Gergely, P., and White, R. N. (1982). “Behavior of reinforced concrete lapped splices for inelastic cyclic loading.” ACI J., 79(5), 355–365.
McLean, D. I., and Smith, C. L. (1997). “Noncontact lap splice in bridge column-shaft connections.”, Washington State Transportation Center, Washington State Univ., Pullman, WA.
Murcia-Delso, J., Shing, P. B., Stavridis, A., and Liu, Y. (2013a). “Required embedment length of column reinforcement extended into type II shafts.”, Dept. of Structural Engineering, Univ. of California, San Diego.
Murcia-Delso, J., Stavridis, A., and Shing, P. B. (2013b). “Bond strength and cyclic bond deterioration of large-diameter bars.” ACI Struct. J., 110(4), 659–670.
Murcia-Delso, J., Stavridis, A., and Shing, P. B. (2015). “Tension development length of large-diameter bars for severe cyclic loading.” ACI Struct. J., 112(6), 689–700.
Priestley, M. J. N. (2003). Myths and fallacies in earthquake engineering, revisited, IUSS Press, Pavia, Italy.
Sagan, V. E., Gergely, P., and White, R. N. (1991). “Behavior and design of noncontact lap splices subjected to repeated inelastic tensile loading.” ACI Struct. J., 88(4), 420–431.
Shima, H., Chou, L., and Okamura, H. (1987). “Bond characteristics in post-yield range of deformed bars.” Proc. JSCE, 6(378), 113–124.
Tepfers, R. (1973). A theory of bond applied to overlapped tensile reinforcement splices for deformed bar, Division of Concrete Structures, Chalmers Univ. of Technology, Goteborg, Sweden.
Tran, H. V., Stanton, J. F., and Eberhard, M. O. (2013). Precast bent system for high seismic regions: Laboratory tests of column-to-drilled shaft socket connections, Federal Highway Administration.
Information & Authors
Information
Published In
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Oct 7, 2015
Accepted: Apr 15, 2016
Published online: Jun 27, 2016
Published in print: Nov 1, 2016
Discussion open until: Nov 27, 2016
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.