Physically Based Model for Evaluation of Rock Scour due to High-Velocity Jet Impact
Publication: Journal of Hydraulic Engineering
Volume 131, Issue 3
Abstract
Scour of rock may occur downstream of dam spillways, as a result of the impact of high-velocity jets. The phenomenon is traditionally assessed by means of (semi-) empirical methods. These partially neglect basic physical processes responsible for rock mass breakup. Therefore, a model to evaluate the ultimate depth and time evolution of scour in jointed rock is presented. The model is based on near-prototype scaled experimental investigations of transient water pressures in artificially created rock joints and on a numerical modeling of the measured pressures. It describes two different ways of rock mass destruction, i.e., failure by instantaneous or progressive breakup of closed-end rock joints, and failure by dynamic ejection of single rock blocks. The corresponding computational methods are easily applicable to practice, without neglecting relevant physics. The basic principles are outlined and applied to the well-known scour hole at Cabora-Bassa Dam.
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Acknowledgments
The writers would like to thank Prof. M. Pirotton and S. Erpicum from the University of Liège, Belgium, for their support during the numerical modeling. The present research project has been partially funded by the Commission for Innovation and Technology (CTI), Bern, Switzerland, with financial support from the Swiss Committee on Dams and Stucky Consulting Engineers Ltd.
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Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 131 • Issue 3 • March 2005
Pages: 153 - 165
Copyright
© 2005 ASCE.
History
Received: Apr 2, 2003
Accepted: Jul 9, 2004
Published online: Mar 1, 2005
Published in print: Mar 2005
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