Boone Dam workers prepare for new construction phases

Brandon Paykamian • Updated Nov 7, 2017 at 4:26 PM

Workers recently started new phases of construction at the Boone Dam repair site and are preparing for building a diaphragm wall to prevent erosion of the earthen berm.

According to a press release from the Tennessee Valley Authority, the dam repair project should be completed by 2022 with a total estimated cost of $450 million. 

Upstream berm activities

TVA spokeswoman Mary Ellen Miller said nearly 36,000 tons of stone from local quarries have been placed to fortify the upstream berm during the first part of construction plans. The additional rock will help fortify the earthen embankment — which is about 900 feet long — ahead of the construction of a diaphragm wall. Miller said the idea behind this phase of the project is to prevent “internal erosion.”

“We’re bringing thousands of pounds of stones sourced from local quarries and fortifying the earthen embankment on both sides,” she said. “It’s a pretty major undertaking.

“Everything we’ve been doing has been in preparation for building that (diaphragm) wall.”

Work is also underway on the downstream side of the dam to move machinery in preparation for the new construction. The next phase of work, according to officials, will be to widen the top of the dam. The construction of the cut-off wall will be completed in the final phase of the project. 

Slurry cell testing and drilling

Drills have been temporarily moved from the top of the dam after TVA completed slurry cell testing. Over the past few months, officials said geologists and engineers have been working to evaluate the underground grout curtain’s ability to contain slurry and provide stability during the construction of the diaphragm wall.

Miller said the main goal of this part of the project was to evaluate the stability of the grout work completed to date, in which over 800 holes were grouted over.

Project manager Sam Vinson said everything looks to be in order.

“The preliminary results are in and they look good in terms of the grout curtain’s ability to contain the slurry,” Vinson said. “This is extremely important to know in advance of building the wall.”

Serving the people: TVA and BrightRidge build Habitat for Humanity home

The first week of October was Public Power Week. To mark the week, volunteer workers from the TVA and BrightRidge, formerly known as the Johnson City Power Board, teamed up to help build a Habitat for Humanity home in Johnson City.

Officials said the future homeowner of the property on Hamilton Street will likely build additions to the home and add “sweat equity” on the home. Holston Habitat spokeswoman Trish Patterson said the new homeowners will be able to purchase the home with no interest after they take home ownership and budgeting classes.

For more information on the Boone Project and other TVA projects, visit their website at www.tva.gov