The award, established in 1997, recognizes excellence among DFI members. The project, which was nominated by two organizations, was selected based on size, scope, and the degree of difficulty and innovation required to complete it.

Workers on the Wolf Creek Dam project celebrate installation of the final piling earlier this year. Their hard work will be recognized by the DFI. Source: Leon Roberts, Army Corps of Engineers

Wolf Creek Dam, which straddles the Cumberland River, is built on a heavily karst bedrock foundation, which presented challenges to the engineers planning the project and the drillers and other contractors executing it. Mike Zoccola, the lead engineer at the Army Corps of Engineers that oversaw the project, said that, as the underlying limestone eroded, “it created an effect like a sinkhole.” The Army Corp had categorized the dam as having a “high risk” of failure prior to beginning the $584 million remediationproject.

National Driller wrote about this project in the April issue. That story said problems with the dam went back to the 1960s.

Drillers installed nearly 1,200 piles as part of the project and filled many underground fissures to make the completed project much stronger. “We knew we were really pushing the envelope on technology,” Zoccola said.

The thrust of the project was a 980,000 square foot concrete barrier wall built using a number of techniques. Those included: high and low mobility grouting, clamshell excavation, hydromill excavation, directional drilled pilot holes, auger drilling, reverse circulation drilling and verification coring drilling.

The completed dam project is now much larger than the old dam, measuring 980,000 total square feet of barrier wall. The team between the Corps and Treviicos-Soletanche Joint Venture was able to complete the work 239 days ahead of schedule.

 The DFI is an international association of contractors, engineers, academics and suppliers in the deep foundations industry with more than 3,300 members worldwide. For more information about the Deep Foundations Institute, visit www.dfi.org.