Scour Depth at Bridges: Method Including Soil Properties. II: Time Rate of Scour Prediction
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 141, Issue 2
Abstract
Scour of the soil by flowing water around bridge supports is the number one reason for bridge collapse. Predicting the depth of the scour hole is an integral part of bridge foundation design, as it impacts the depth of the piles. Indeed, the scour depth must be ignored in the vertical and horizontal resistance of the piles. This paper presents a method to predict the progression of the scour depth around bridge supports as a function of time when subjected to a velocity hydrograph. It also addresses the issue of layered soils. The equations make use of the commonly used water velocity and dimensions of the obstacle, but add a new and important component: the soil erosion function to characterize the degree of soil resistance to erosion. The equations apply to pier scour, contraction scour, and abutment scour. The predicted output is the scour depth as a function of time for a given velocity hydrograph and soil layer stratigraphy. A comparison between measured and predicted scour depth is presented, but more comparisons are necessary, particularly at full scale.
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Acknowledgments
The author acknowledges all the Ph.D. students who worked on this topic over the years. In chronological order, they are Rao Gudavalli, Kiseok Kwak, Prahoro Nurtjahyo, Gensheng Wei, Yiwen Cao, Ya Li, Jun Wang, Seung Jae Oh, Xingnian Chen, Anand Govindasamy, and Congpu Yao. The author also thanks the main agencies that sponsored this work over the years: the Texas DOT (John Delphia, Mark McClelland) and NCHRP (Tim Hess) and colleagues at Texas A&M University (Hamn-Ching Chen, Kuang-An Chang).
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Information & Authors
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 141 • Issue 2 • February 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Feb 10, 2014
Accepted: Sep 19, 2014
Published online: Oct 30, 2014
Published in print: Feb 1, 2015
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