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Projects

Center Hill Dam Rehabilitation

USACE turns to IntelliGrout® technology to address high-risk seepage challenge head on.

  • Cave features in the hillside adjacent to the dam were identified as potential cause of active seepage-Gannett Fleming

    Cave features in the hillside adjacent to the dam were identified as potential cause of active seepage.

Client
U.S. Army Corps of Engineers, Nashville District 

Partner(s)
Kiewit-Advance Construction Techniques, Ltd., joint venture

Location
Smithville, Tennessee

Our Role
Quality Control, Technical Oversight, Grouting.

Data
Size
2,160 feet long, 250 feet high
Construction Cost
$95 million
Completed
2011
Duration
5 years
Outcomes
  • Installation of grout curtains controlled seepage and facilitated slurry wall construction
  • Oversaw design and construction of soil nail walls and slope stabilization measures.

Center Hill Dam provides flood control, navigation, hydropower, recreation, water supply, and water quality benefits. Because of its highly solutioned limestone foundation and rims, seepage problems have plagued the Center Hill Dam since the first test filling of the reservoir. Cavernous features are known to exist at the site, and active seepage conditions from springs and caves located on both abutments downstream of the dam have significant discharge.

What We Did

As a subcontractor and subconsultant to the Kiewit-ACT joint venture, Gannett Fleming provided a team of engineers and geologists for quality control services and technical oversight during drilling and grouting operations. These operations are being monitored using the patented IntelliGrout technology, which was jointly developed by Gannett Fleming and ACT.

The project included installation of a double-line grout curtain in the embankment foundation to control seepage and facilitate future slurry wall construction, installation of the triple-line grout curtain along the left groin foundation, installation of a cave barrier along portions of the left rim, and installation of triple- and single-line grout curtains along the remaining left rim. Gannett Fleming was also obtained readings on 36 existing piezometers that the USACE identified as critical dam safety instruments. Gannett Fleming automated these existing instruments and integrated this data into the IntelliGrout® system – that provides readings every two minutes to the IntelliGrout® operators and features capabilities to generate instrument time trend reports. This allowed monitoring of critical dam safety indicators during drilling and grouting activities to gauge the performance of the foundation treatment.

Key Features

  • Developed automated system of existing instrumentation to permit real-time observation of the dam safety instruments during the grouting operations

  • Obtained readings on 36 existing piezometers that the USACE identified as critical dam safety instruments

  • Designed, installed, and programmed an automated instrumentation system with readings available every two minutes to the IntelliGrout® operators that features capabilities to generate instrument time trend reports.

Similar Projects: Dams & Levees: Dam Risk & Reliability Assessments, Water/Wastewater: Dams & Levees, Geotechnical, Geotechnical: Ground Modification, Geotechnical: Grouting, Geotechnical: Retaining Walls, Geotechnical: Seepage Remediation