Post-tensioned stabilization of Roy Inks Dam

Roy Inks Dam is a high hazard, concrete gravity dam located on the Colorado River near Burnet, Texas. The dam, constructed from 1936 to 1938, is owned and operated by the Lower Colorado River Authority (LCRA). During the LCRA Dam Modernization Program, the extreme flood events were reevaluated for the Highland Lakes Dams. As a result, Inks Dam was found to be subject to a more severe loading condition than was considered in the original design. The dam's stability was analyzed under the new loading conditions and stabilization improvements were designed to protect the 880 feet long, uncontrolled, ogee-shaped spillway.

Construction improvements to the dam included removal of the top lift of the spillway, construction of a reinforced concrete stressing beam, installation of forty-six 24-strand (1000 kip) post-tensioned anchors, and reconstruction of the crest of the dam. The project also included an 18-inch pipeline penetration through the dam to relocate an existing USFWS Fish Hatchery water supply line.

This paper provides an overview of the challenges presented to the design team due to the unique nature of this project and the existing condition of the structure. It also presents a discussion of the construction and addresses how lessons learned from previous post-tensioned spillway anchoring projects were incorporated. 11 pp., 8 figures.