skip to content
Projects

Center Hill Dam Rehabilitation

Soil nailing resolved an unforeseen subsurface condition issue quickly and efficiently while enabling stabilization of the steep embankments.
  • Soil nailing reduced excavation by stabilizing a rock slope that would otherwise have been removed-Gannett Fleming

    Soil nailing reduced excavation by stabilizing a rock slope that would otherwise have been removed.

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
  • Soil nail walls stabilized slopes provided access to perform grouting activities
  • Coordination of highly complex drilling and grouting operation using IntelliGrout® 
  • Installation of grout curtains controlled seepage and facilitated slurry wall construction.

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 were being monitored using the patented IntelliGrout technology, which was jointly developed by Gannett Fleming and ACT.

In addition to grouting operations, Gannett Fleming oversaw the design and construction of soil nail walls and rock slope stabilization measures when falling rocks prevented access to the left rim foundation for grouting activities. Mindful that this work was critical to maintaining the cost and schedule of the project, soil nailing was suggested as an alternate method to resolve the issue quickly and efficiently. The suggestion resolved the matter, saved the project precious time, and enabled the stabilization of the steep embankment.

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
  • Automated existing instruments and integrated data into the IntelliGrout system 
  • Automated instrumentation system generates readings every two minutes to the IntelliGrout operators providing the ability to produce 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, Water/Wastewater