Photo by Todd Harrell/National Guard
Geotechnical engineering project won kudos upon 2008 completion but failed in 2015.

The failure in March of a geosynthetically reinforced runway extension at Charleston, W.Va.'s Yeager International Airport has triggered a lengthy dispute among the facility's insurance carrier, designer Triad Engineering and contractor that will involve millions in damages.

The damage liability involving insurer AIG Aero, Triad Engineering, Scott Depot, W. Va., and Pennsylvania contractor Cast and Baker now is estimated at $16 million to $26 million.

"It's been 55 days since the incident, and we have yet to see an adjuster from any party here at the site," Michael Plante, Yeager airport spokesman, said on May 12.

At a special airport board meeting this month, Plante said Yeager refinanced its debt and began to settle claims from displaced residents because of delays in negotiations between the insurance companies representing the airport and its contractors. "AIG has told us that the airport is not at fault, and we like hearing that, but we want the community made whole," he said.

At least one contractor, SE Clearing and Hydroseeding, was hired to perform recovery work on the condition it would be paid when the insurance is settled, Plante told ENR.

Hailed as a geotechnical marvel of modern engineering when it was completed in 2008—the highest geotechnically reinforced slope in the U.S.—it collapsed on March 12, forcing the evacuation of more than 100 residents. Several homes down slope were destroyed and a creek flooded.

TenCate Geosynthetics, a leading global geosynthetic materials company that supplied a specialized mesh for the $25-million project, said the runway apron won an Award of Excellence in the geosynthetic projects category of the 2007 International Achievement Awards from Industrial Fabrics Association International.

An association official, Christine Gerard, said the competition is judged by industry experts on creativity, function, design uniqueness and complexity.

The technology proved its efficacy in 2010, when the runway extension was credited with saving 34 people after a plane overran the runway on an aborted takeoff.

Completed in 1947, Yeager is sited on a man-made plateau atop rugged, mountainous terrain. New Federal Aviation Administration regulations in the early 2000s, however, threatened its continued operation.

Required improvements included adding 500 ft of emergency-stop apron for Runway 5, which meant working on a mountainside that slopes down steeply more than 300 ft to the Elk and Kanawha rivers.

"The entire slope did not fail," Plante says. The next steps are to deal with the collapsed slope and issue a request for qualifications to hire a contractor to restore the extension to a capacity that meets FAA regulations, he said.

Important Case Study

"I do believe the failure of this slope will have a major impact on the future of geotechnical engineering," says George Koerner, director of the The Geosynthetic Institute, a Folsom, Pa., industry trade and research group.

George Koerner, director of the Geosynthetic Institute, a trade organization - See more at: says. "It will cause designers to be much more conservative in their consideration of drainage and other hydraulic factors, which appear, at this point, to be the cause of the failure. It's been distressed. They've known for sometime it was distressed."

"We received two to three inches of rain in the days before the collapse, and a state of emergency for flooding was declared by the governor," Plante says. The airport does not know if that contributed to it, but there was a significant weather event at the time.

Rick Valentine, Triad's consultant, told ENR he could not share any of the findings from his investigation into the cause of the slip.

Fine-grain soil products available as fill material on similar projects also will receive more scrutiny from designers in the future, says Koerner. The slope was filled with 1.5 million cu yd of dirt, Tencate says.

John Lustombo, TenCate's market manager, said stormwater detention was not part of the company's work on Yeager airport.

Triad Engineering and Cast & Baker did not return ENR's requests for comment.