Cairo, GA: Soil-Bentonite Slurry Wall, Tired Creek Dam
In 2010, Grady County, Georgia secured a permit from the U.S. Army Corps of Engineers to construct a 960-acre recreational lake at the confluence of three creeks which combine to form Tired Creek. Tired Creek is a tributary of the Ochlockonee River. Construction of the lake will include a 3,000 foot long, 450 foot wide, 65 foot high dam that will contain the proposed Tired Creek Lake.
Geo-Solutions Inc. was contracted by Brad Cole Construction to install a soil-bentonite slurry wall to serve as the core trench for the future dam. The vertical barrier included the installation of 74,400 vertical square feet (vsf) of soil-bentonite (SB) slurry wall. The wall was installed to an average depth of 34 feet below ground surface (fbgs).
Excavation was accomplished under bentonite slurry using a Komatsu PC800 excavator and Geo-Solutions' long-reach stick attachment. Bentonite slurry for trenching was produced on site in Geo-Solutions' custom-made batch plant and pumped to the trench. The SB wall was 2,200 feet in length.
Trench spoils were blended with bentonite slurry as well as additional dry bentonite placed alongside the trench to create a controlled backfill mix. The target permeability for the SB wall was an average of 1 x 10-7. Target permeability was attained with an overall average permeability of 2.97 x 10-8.