Maximum Impact Force of Woody Debris on Floodplain Structures
Publication: Journal of Hydraulic Engineering
Volume 130, Issue 2
Abstract
We collided woody debris (i.e., logs) with structures using flume and test basin laboratory facilities to investigate the maximum impact force that floodplain structures are exposed to from floating woody debris. The tests also investigated the influence of collision geometry, determined by the debris orientation on impact, on the maximum impact forces. We reviewed the three approaches that represent the existing guidance for estimating maximum impact forces. Each approach estimates the maximum impact force based on the debris velocity and mass. We show that all the existing approaches can be derived from a single-degree-of-freedom model of the collision and can be considered to be equivalent. The laboratory data show that the maximum impact force was associated with a log striking a rigid structure with its end. Oblique and eccentric collisions reduced the maximum impact load in a predictable and consistent manner. The approach we refer to as “contact stiffness,” a linear, one-degree-of-freedom model with no damping, was able to reproduce the laboratory results over the entire range of data, with an effective contact stiffness of 2.4 MN/m.
Get full access to this article
View all available purchase options and get full access to this article.
References
American Association of State Highways and Transportation Officials (AASHTO). (1998). “LRFD bridge design specifications.” 2nd Ed., Washington, D.C., 26–27.
Federal Emergency Management Agency (FEMA). (1995). “Engineering principles and practices for retrofitting floodprone residential buildings.” FEMA Rep. No. 259, Washington, D.C.
Haehnel, R. B., and Daly, S. F. (2002). “Maximum impact force of woody debris on floodplain structures.” Rep. No. ERDC/CRREL TR-02-2, USA Cold Regions Research and Engineering Laboratory, Engineering Research and Development Center, Hanover, N.H. 〈http://www.crrel.usace.army.mil.techpub/CRREL Reports/reports/TR02-2.pdf〉.
Matskevitch, D. G.(1997). “Eccentric impact of an ice feature: Linearized model.” Cold Regions Sci. Technol., 25, 159–171.
National Association of Australian State Road Authorities (NAASRA). (1990). “Highway bridge design specification.”
Sarpkaya, T., and Isaacson, M. (1981). Mechanics of wave forces on offshore structures, Van Nostrand–Rienhold, New York.
U.S. Army Corps of Engineers. (1995). “Flood-proofing regulations.” Engineering Pamphlet 1165-2-314, Washington, D.C.
Information & Authors
Information
Published In
Copyright
Copyright © 2004 American Society of Civil Engineers.
History
Received: Sep 17, 2002
Accepted: Jul 8, 2003
Published online: Jan 16, 2004
Published in print: Feb 2004
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.