Corps to seek concrete seepage barrier at 135-MW Center Hill

The Corps of Engineers plans to seek bids for construction of a concrete seepage barrier at the main embankment of 135-MW Center Hill Dam on the Caney Fork River near Lancaster, Tenn.

A solicitation is expected to be issued about Jan. 22, 2010, for the work at Center Hill, which has a history of seepage problems that have worsened in recent years. The Corps’ Nashville District awarded an $87.4 million contract in 2008 to Kiewit—A.C.T. to install a grout curtain seepage barrier at the project. (HydroWorld 2/28/09)

The 250-foot-tall dam consists of a 1,382-foot-long concrete section and 778-foot-long earth embankment. The Corps said the expected solicitation would call for a 900-foot-long concrete seepage barrier with a minimum 2-foot thickness, extending from elevation 696 mean sea level to 405 msl.

The barrier is to be installed through existing earthen embankment and underlying limestone foundation. Portions of the limestone foundation exhibit unconfined compressive strengths up to 40,000 pounds per square inch, with an average of 16,000 psi. Therefore the Corps prefers a combined wall of hydromill and circular pile elements.

Center Hill Dam is among six dams the Corps identified as having a high risk of failure, in a screening program of 130 dams. In 2006, the Corps approved a $240 million rehabilitation plan to improve the dam’s long-term reliability by 2014.

A pre-solicitation notice may be obtained from the Federal Business Opportunities Internet site, www.fbo.gov, by entering Solicitation No. W912P509R0011 in the “Keyword/Solicitation #” box.

For information, contact Yvette Walker, U.S. Army Engineer District, Nashville, P.O. Box 1070, 801 Broad St., Nashville, TN 37202-1070; (1) 615-736-7944; E-mail: [email protected].