American Society of Civil Engineers

Over the Top Concrete

by Glen McDonald, P.E., (Chf. of the State Water Projects Bureau, Montana Dept. of Natural Resour. and Conservation, Helena, MT) and Douglas Yadon, P.E., M.ASCE, (Dir. of Engrg., ESA Consultants Inc., Bozeman, MT)

Civil Engineering—ASCE
, Vol. 68, No. 1, January 1998, pp. 72-75

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Document type: Feature Article
Abstract: The 60-year-old Tongue River Dam in southeastern Montana is undergoing extensive dam safety and reservoir enlargement modifications. Major features of the project include a 60,000 cfs roller compacted concrete stair-step emergency spillway over the dam, a 40,000 cfs labyrinth weir primary spillway, and a new primary outlet tunnel. The article focuses on the use of roller compacted concrete for the emergency, over-the-top spillway. At 72.5 ft from crest to stilling basin floor, the spillway will be one of the highest roller compacted concrete overtopping protections built on an existing earthen-fill dam.

ASCE Subject Headings:
Dam safety
Roller-compacted concrete