The Final Piece of the Puzzle: Re-Design of Grouted Closures for a Dam Cutoff Wall-Paper

Paper

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Buckeye Lake Dam in Ohio underwent major rehabilitation from 2015 to 2018 to address seepage, instability, and overtopping risks. The new seepage cutoff system combined soil-mix walls, sheet piling, and concrete structures, but eight gaps remained at spillways and the North Shore Abutment. These closures were needed to prevent seepage from bypassing the cutoff.<br /><br />The original design called for low-pressure chemical permeation grouting using acrylate and polyurethane grouts. This approach was considered cautious but potentially slow, costly, and difficult to verify, particularly because the site contained highly variable, interbedded soils. The specialty contractor proposed jet grouting instead, which could treat a broader range of soils, create a stronger and more uniform low-permeability mass, and avoid the iterative treatment process anticipated for chemical grouting.<br /><br />The project installed 26 jet-grout elements, 15 to 45 feet deep, in overlapping rows. Risk controls included real-time movement monitoring, procedures to stop work if movement or surface connections occurred, and containment and removal of grout spoils. Minor surface connections and approximately 0.25 inches of localized heave were observed; operations were paused, investigated, and resumed without damage to structures.<br /><br />Verification cores showed generally continuous columns. All nine verification locations met the specified acceptance criteria: permeability was below 0.2 gallons per day per square foot, and compressive strength exceeded 100 psi. The work was completed in a short timeframe while other construction proceeded nearby.<br /><br />The paper concludes that jet grouting can be used safely around dams when site conditions and risks are carefully assessed, experienced personnel are involved, and robust monitoring and clear stakeholder communication are maintained. It also emphasizes that monitoring should be automated where possible, and that crews must be prepared to halt operations quickly if unexpected conditions arise.

Keywords

Buckeye Lake Dam

jet grouting

seepage cutoff

dam rehabilitation

Ohio

grout verification

soil-mix walls

sheet piling

permeability

construction monitoring