Publication Abstract

Proceedings of the 43rd Annual Conference on Deep Foundations, 2018, Anaheim, CA, USA, (DFI)

Wanapum Dam Repaired Using Post-Tensioning Anchors
Abigail Stein, Assistant Project Manager, Aled Hughes, P.E., Principal, Civil Engineer, Rick Deschamps, P.E., Ph.D., Vice President of Engineering, Brian Barkauskas, P.E. and Business Development Director

In central Washington, six miles south of the small town of Vantage, the flow of the Columbia River is harnessed by the Wanapum Dam which is part of the Priest Rapids Hydroelectric Project owned and operated by Grant County Public Utility District (GCPUD). Extending more than 8,300-feet from bank to bank, the dam includes left and right earth embankments, left and right concrete gravity sections and a 10-unit powerhouse. Adjacent to the right embankment is a concrete gravity spillway featuring radial gates measuring 50-feet-wide and nearly 70-feet-high. In the early 1960ís when Wanapum Dam was built, these seven-story spillway gates were the highest in the world. In late February 2014, 50-years into its service life, during a routine maintenance inspection, observant workers noticed a slight misalignment in the roadway deck curbs and handrails located on top of the spillway. Further survey and inspection efforts uncovered a 65-foot-long by twoinchwide crack that spanned the full length of Monolith 4.

 article #3114; publication #1045 (AM-2018)