Spillway and Stilling Basin for The Dalles Dam, Columbia River, Oregon and Washington: Hydraulic Model Investigation
Spillway and Stilling Basin for The Dalles Dam, Columbia River, Oregon and Washington: Hydraulic Model Investigation

Author: ARMY ENGINEER DIV NORTH PACIFIC BONNEVILLE OREG DIV OF HYDRAULIC LAB.

Publisher:

Published: 1964

Total Pages: 119

ISBN-13:

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The concrete-gravity ogee spillway of The Dalles Dam contains twenty-three 50-ft-wide bays separated by 10-ft-wide crest piers. The crest is designed to pass 2,290,000 cfs under a total head of 61.3 ft; the crest shape is designed for 75 per cent of maximum head or 46.0 ft. A 170-ft-long, hydraulic jump-type stilling basin, with one row of 9-ft-high baffle piers and a 13-ft-high end sill, will dissipate excess energy of spillway flows to and including the project design discharge of 2,290,000 cfs. The hydraulic performance of various elements for the spillway and stilling basin was studied in a 1:36-scale model.

Spillway and Stilling Basin John Day Dam, Columbia River, Oregon and Washington. Hydraulic Model Investigation
Spillway and Stilling Basin John Day Dam, Columbia River, Oregon and Washington. Hydraulic Model Investigation

Author:

Publisher:

Published: 1974

Total Pages: 0

ISBN-13:

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Two sectional models were used to check performance of the proposed spillway for John Day Dam and to develop improvements if necessary. A three-bay section of the 20-bay spillway was studied in a 1:41.14-scale model. A two-bay section of the 17 low bays to be used during second-step construction was reproduced in a 1:24-scale model. Modifications of the crest piers to reduce the danger of cavitation during unusually large spillway flows were recommended. Discharge ratings in the three-bay model indicated that capacity of the spillway was slightly greater than computed for the design flow of 2,250,000 cfs. A 185-ft-long stilling basin at elev 114 performed as well as a 210-ft-long basin at elev 118. Three 10-ft-high baffle piers produced desired flow conditions in bay 2 of the stilling basin.

Spillway and Stilling Basin for McNary Dam, Columbia River, Oregon and Washington; Hydraulic Model Investigations
Spillway and Stilling Basin for McNary Dam, Columbia River, Oregon and Washington; Hydraulic Model Investigations

Author: ARMY ENGINEER DIV NORTH PACIFIC BONNEVILLE OREG DIV OF HYDRAULIC LAB.

Publisher:

Published: 1961

Total Pages: 111

ISBN-13:

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The hydraulic performance of the spillway for McNary Dam was studied in two models having respective scale ratios of 1:36 and 1:10. Special attention was given to the capacity of the spillway and stilling basin to ensure that the desired flow could be passed safely. Tests of the original spillway design indicated that the spillway capacity was at least 10 per cent greater than assumed in the design analysis and that revisions of the piers would improve flow conditions and reduce the possibility of cavitation adjacent to the gate slots.