During construction of a concrete dam, floods are often passed over partially completed spillway crests. These flow conditions are very different from the design and have the potential to cause large scale damage. The jet of water springs from the downstream edge of the truncated spillway and impinges on the floor of the energy dissipator at the toe of the spillway can cause damage. Some arrangement is needed to make the nappe cling to the spillway profile for as high a discharge as possible. Hydraulic model studies at Central Water and Power Research Station (CWPRS), Pune, India, have demonstrated the usefulness of temporary crests in the form of humps at the downstream edge of the truncated spillway to guide the flow and minimise the damage. This paper focuses on the discharge characteristics of a partly completed spillway and the role of temporary crests during construction of concrete dam spillways.

Want to read the full paper?

To purchase a copy of this Dam Engineering paper, please email the Editor, Carrieann Davies, on: cdavies@wilmington.co.uk or fax: +44 (0) 20 8269 7804.
The cost is £20 sterling for each paper, postage & handling free.
Your order will be confirmed by email. We aim to dispatch your order within 48 hours of receipt.