Post-Tensioned Stabilization of Roy Inks Dam - Nicholson ...

POST-TENSIONED STABILIZATION OF ROY INKS DAMJohn S. Wolfhope, P.E.Project ManagerFreese and Nichols, Inc.jsw@freese.comJerome W. Scanlon, P.E.AssociateFreese and Nichols, Inc.jws@freese.comGregor ForbesProgram ManagerLower Colorado River Authoritygforbes@lcra.orgRoger A. BaldwinProject ExecutiveNicholson Constructionrbaldwin@nicholson-rodio.comABSTRACTRoy Inks Dam (Inks Dam) is a high hazard, concrete gravity dam located on theColorado River near Burnet, Texas. The dam, constructed from 1936 to 1938, isowned and operated by the Lower Colorado River Authority (LCRA). During theLCRA Dam Modernization Program, the extreme flood events were reevaluatedfor the Highland Lakes Dams. As a result, Inks Dam was found to be subject to amore severe loading condition than was considered in the original design. Thedam’s stability was analyzed under the new loading conditions and stabilizationimprovements were designed to protect the 880 feet long, uncontrolled, ogeeshapedspillway.Construction improvements to the dam included removal of the top lift of thespillway, construction of a reinforced concrete stressing beam, installation offorty-six 24-strand (1000 kip) post-tensioned anchors, and reconstruction of thecrest of the dam. The project also included an 18-inch pipeline penetrationthrough the dam to relocate an existing USFWS Fish Hatchery water supply line.This paper provides an overview of the challenges presented to the design teamdue 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 lessonslearned from previous post-tensioned spillway anchoring projects wereincorporated.