TVA Dams Structural Modifications Program - Six Dams
Technology and geotechnical understanding have advanced significantly since the Cherokee, Douglas and Fort Loudoun dams were constructed on fast-track schedules to support the War Effort and energy advancement in the early 1940s. So before the Tennessee Valley Authority (TVA) could proceed with bringing a second nuclear reactor online at its Watts Bar facility downstream, the Nuclear Regulatory Commission wanted to ensure that certain dams within the TVA system were modified for Probable Maximum Flood and correct Seismic Loadings by today’s standards. TVA recently marked 80 years of providing electricity and flood control for the 9 million customers within the greater Tennessee Valley. TVA’s ultimate goal is to provide 1,100 MW of additional power to its seven-state service area.
To ensure that TVA meets this goal and that power and recreational users can be confident in the stability of Cherokee, Douglas, Fort Loudoun, Watts Bar, Tellico and Douglas Saddle dams, Barnard embarked on a Structural Modifications Program with TVA. Our team installed 84 anchors into bedrock on the training wall, dam spillway and non-spilling sections of Cherokee Dam. We worked from a specially designed and fabricated steel work platform that was anchored to the spillway face to support the drilling, grouting and support equipment for some of these anchors. At Douglas Dam, 20 anchors were installed vertically through a non-overflow section of the dam. And at Fort Loudoun Dam, the project team installed 27-strand post-tensioned anchors 150 feet deep through the neck of the dam. Additionally at all three dams, our team modified, enlarged or removed and replaced the existing concrete floodwalls with taller and stouter concrete floodwalls. These new concrete floodwalls total 2,680 LF and 4,177 CY of concrete and range in size from 14 feet tall x 3 feet wide to 20 feet tall x 3.5 feet wide at Cherokee and Douglas Dams and 8 feet tall x 1-foot 8 inches wide at Fort Loudoun. We teamed with Nicholson on these fast-track projects.
In fact, Barnard has now worked on 13 TVA projects under 8 contracts, including some modifications to one lock and another dam-strengthening project outside of the Structural Modifications Program.