That phase of construction included utilizing 36,000 tons of stone to fortify the upstream berm to prevent internal erosion, as well as slurry cell testing to evaluate the stability of the grout work completed to date. All of this, according to officials, was in preparation for building the diaphragm wall and retainment wall.
“The project is ultimately about maintaining the safety of the downstream public and the safety of workers as we repair this dam,” Program Manager Mary Ellen Miller said. “We want to safely and efficiently repair this dam.”
Miller said the painstaking work to finish the Boone Dam project is still on track to be finished in 2022, according to projections.
“It’s going very well and everything is progressing according to plan,” she said.
As for the construction of the diaphragm cut-off wall, Miller said officials are expecting to announce who the contractor for that stage of the project will be in the fall, when they hope work will quickly proceed from there.
Workers at the Boone Dam project have recently started building a retaining wall to protect and provide access to the control building during downstream berm construction. The wall will be assembled block-by-block, much like “giant, real-life LEGO pieces,” officials said in a press release.
“The new retaining wall, built on the downstream side of Boone Dam, will protect and provide access to the control building during downstream berm construction,” Miller said.
Throughout the coming weeks, thousands of tons of rock will be placed on the downstream side of the embankment. So far, much of the work has taken place on the upstream berm, according to officials.
In an effort to avoid putting too much stress on either side of the embankment, work will alternate between the upstream and downstream sides of the dam.
“We expect to continue placing rock on the upstream and downstream sides of Boone Dam throughout the spring,” Miller said. “During this phase of construction, we are placing rock to add stability to the earthen embankment prior to construction of the diaphragm wall.”
To date, more than 110,000 tons of rock have been hauled to the site to complete the project.
In a February press release, TVA officials answered frequently asked questions about the project. One thing that many locals have asked is why there are some days when much of the work is halted.
Locals also asked why workers often only work during the day.
“The construction of the upstream and downstream berms follow a particular engineering sequence designed to protect the earthen dam while safely creating the berms. The work started on the upstream side but has now shifted to the downstream side of the project,” TVA wrote in the press release.
“The work you’ve seen recently on the upstream side is in preparation to shift berm construction back to that area later this spring.
“As for working overnight, the nature of the berm construction and the locations where it is currently being performed make it unsafe to move heavy equipment and rock at night. When we complete the berm construction and begin construction of the cutoff wall, we will again return to overnight work.”
For more updates on the Boone Dam project, visit www.tva.gov/Newsroom/Boone-Dam-Project.