Evaluation of Remediation Techniques for Circular Holes in the Webs of Wood I-Joists
Publication: Journal of Materials in Civil Engineering
Volume 25, Issue 12
Abstract
Remediation methods and strength predictions were evaluated for wood I-joists with single, circular holes in the webs, leaving utilities in place. A full-scale bending test using four equally spaced point loads was applied to three depths of joists with varying flange widths and span lengths of 4.88 and 2.44 m. Failure modes for long-span joists without holes were in the flanges in tension, compression, or lateral buckling, but once a hole was introduced, the majority failed in shear. The curved beam approach and manufacturers software were used to predict strength. Seven remediation techniques were investigated initially, and remediation effectiveness was evaluated on the basis of strength, stiffness, and ease of installation/cost. The oriented strand board (OSB) collar remediation worked very well and returned 8 of 12 series of joists to a strength statistically equivalent to the “no hole” condition. The OSB collar was not quite as effective in returning stiffness to the joists but was easier to install and less expensive than a laminated strand lumber patch.
Get full access to this article
View all available purchase options and get full access to this article.
References
Afzal, M. T., Lai, S., Chui, Y. H., and Pirzada, G. B. (2006). “Experimental evaluation of wood I-joists with web holes.” For. Prod. J., 56(10), 26–30.
ASTM. (2010b). “Standard practice for sampling and data-analysis for structural wood and wood-based products.” D2915, West Conshocken, PA.
ASTM. (2012). “Standard specification for establishing and monitoring structural capacities of prefabricated wood I-joists.” D5055, West Conshohocken, PA.
Bower, J. E. (1966). “Elastic stresses around holes in wide-flange beam.” J. Struct. Div., 92(2), 85–101.
Chan, P. W., and Redwood, R. G. (1974). “Stresses in beams with circular eccentric web holes.” J. Struct. Div., 100(1), 231–248.
Cheng, R. J. (1996). “Design of OSB webbed I-joists with web opening.” Proc. of the Int. Wood Engineering Conf., Louisiana State University, Baton Rouge, LA, 134–141.
Clinch, R. W. (1993). “Effect of holes on static flexural stiffness of a wood composite I-beam.” For. Prod. J., 43(10), 23–28.
Guan, Z. W., and Zhu, E. C. (2009). “Finite element modelling of anisotropic elasto-plastic timber composite beams with openings.” Eng. Struct., 31(2), 394–403.
Huston, R., and Josephs, H. (2009). “Curved beams.” Practical stress analysis in engineering design, 3rd Ed., Taylor & Francis Group, Boca Raton, FL, 199–210.
Knostman, H. D., Cooper, P. B., and Snell, R. R. (1977). “Shear force distribution at eccentric web openings.” J. Struct. Div., 103(6), 1207–1221.
LabView 2010 [Computer software]. National Instruments, Austin TX.
Lewis, W. C., Heebink, T. B., and Cottingham, W. S. (1944). “Effects of certain defects and stress-concentrating factors on the strength of tension flanges of box beams.”, Forest Products Laboratory, Madison, WI.
Morrissey, G. C., Dinehart, D. W., and Gary Dunn, W. (2009). “Wood I-joists with excessive web openings: An experimental and analytical investigation.” J. Struct. Eng., 135(6), 655–665.
Pirzada, G. B., Chui, Y. H., and Lai, S. (2008). “Predicting strength of wood I-joist with a circular web hole.” J. Struct. Eng., 134(7), 1229–1234.
Polocoser, T. (2012). “Evaluation of remediation techniques for circular holes in the webs of wood I-joists.” M.S. thesis, Oregon State Univ., Corvallis, OR.
Smith, C. B. (1944). “Effect of elliptic or circular holes on the stress distribution in plates of wood or plywood considered as orthotropic materials.”, USDA Forest Service, Forest Products Laboratory, Madison, WI.
Wang, S. (1994). “Shear behavior of OSB composite I-Beams with web openings.” M.S. thesis, Univ. of Alberta, Edmonton, AB, Canada.
Wood I-Joist Manufacturers Association (WIJMA). (1999). “Establishing shear capacities for prefabricated wood I-joists with hole.” 〈http://i-joist.org/policies-publications〉 (Feb. 28, 2012).
Zhu, E. C., Guan, Z. W., Rodd, P. D., and Pope, D. J. (2005a). “Buckling of oriented strand board webbed wood I-beams.” J. Struct. Eng., 131(10), 1629–1636.
Zhu, E. C., Guan, Z. W., Rodd, P. D., and Pope, D. J. (2005b). “Finite element modeling of OSB webbed timber I-beams with interactions between openings.” Adv. Eng. Softw., 36(11–12), 797–805.
Zhu, E. C., Guan, Z. W., Rodd, P. D., and Pope, D. J. (2007). “Structural behaviour of OSB webbed timber I-beams with openings.” J. Struct. Eng., 133(1), 145–149.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 25 • Issue 12 • December 2013
Pages: 1898 - 1909
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jul 26, 2012
Accepted: Nov 16, 2012
Published online: Nov 20, 2012
Discussion open until: Apr 20, 2013
Published in print: Dec 1, 2013
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.