Modeling the Erosion and Swelling of the Sides of Transverse Cracks in Embankment Dams
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 145, Issue 5
Abstract
Concentrated leak erosion occurs in transverse cracks in dams when the reservoir rises above the base of the cracks. As water flows through the crack, the sides of the crack will erode if the hydraulic shear stress exceeds the critical shear stress of the soil, and the crack will widen. For cracks above the phreatic surface, the sides of the partially saturated soil in the sides of the cracks will swell with increasing moisture content, narrowing the crack. These two phenomena occur concurrently. Laboratory erosion and swell tests have been carried out on five soils which are representative of the soils used in the core of embankment dams. Using this data and the equations controlling the rate of erosion, crack width versus time has been modelled. This shows that for the soils tested the crack will close for cracks up to about 5 mm wide for a flow gradient of 0.1, and 1 mm to 2 mm wide for a flow gradient of 0.4. For wider cracks the erosion will progress.
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Acknowledgments
This research was carried out with funding provided by Australian Research Council (LP110100389), University of New South Wales, Department of Public Works, Dam Safety Committee of New South Wales, Murray Darling Basin Authority, Water Corporation, Southern Water, now TasWater, Hydro Tasmania, Melbourne Water, Goulburn-Murray Water, SunWater, URS Australia, now AECOM, GHD, SMEC Australia, and Elforsk.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 145 • Issue 5 • May 2019
Copyright
©2019 American Society of Civil Engineers.
History
Received: Apr 6, 2018
Accepted: Oct 23, 2018
Published online: Feb 22, 2019
Published in print: May 1, 2019
Discussion open until: Jul 22, 2019
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