U.S. 129 Slide Repair Update for April 20

 

KNOXVILLE, Tenn. - The Tennessee Department of Transportation’s emergency contractor Pacific Blasting & Demolition Ltd. continues working to remove unstable rock from of the slope above U.S. 129/SR-115 in Blount County. A section of U.S. 129 from the Foothills Parkway to the Tabcatt Bridge was closed on March 14 after a major rockslide. 

 

Since work began on April 6, crews have removed approximately 1,500 cubic yards of unstable rock from the face of the slope. The scaled rock combined with the material that has already fallen from the unstable slope has left an estimated 4,000 cubic yards of rock on the roadway. 

 

Today, crews are expected to begin hauling away rock and debris along the roadway. However, a large rock berm will remain in place to help prevent falling rock from entering Chilhowee Lake. 

 

During the scaling process, TDOT geotechnical engineers and contractors have located another area that will need to be trim blasted. This week, crews with Pacific Blasting and Demolition plan to trim blast three areas to remove unstable rock that could endanger workers during the rock bolting phase of the project.  Trim blasting, is low-impact blasting technique used to carefully tap a loose boulder and get it to fall apart and fall down the slope. Workers drill holes in strategic locations around the targeted rock and insert a small quantity of explosives to remove the rock. Trim blasting is being used on this project to minimize flying rock debris and to avoid causing further damage to the mountainside.

 

Meanwhile, rock scaling workers are using other methods to remove boulders from the mountainside. Crews have used a method called “air bagging” which allows workers to insert airbags into cracks and crevices of loose rock, inflate them, and force the loose rock to fall from the slope. The same airbags are used by rescue crews to lift vehicles off the ground when a motorist is trapped inside.  Trained workers are also using a scaling bar to remove some of the most unstable rock and debris by hand.

 

Detours remain in place while work to stabilize the slope and remove the rockslide continues. The completion date for the project remains July 31, with a $195,000 incentive for early completion by July 1.

 

TDOT has created a web page for information on the rockslide which can be found at www.tn.gov/tdot by clicking on the link "Rockslide Closures" at the top of the page. Motorists can find detour maps for all rockslides currently effecting travel in Tennessee. TDOT will also use the site to communicate updates on the project to stabilize and clear the U.S. 129 slide.

 

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