A Virginia Department of Transportation (VDOT) employee with the Staunton District spotted a sinkhole on Interstate 64 near mile marker 93 in Augusta County around 3 p.m. June 19.
As part of its VDOT maintenance district-wide contract, Byer, Harmon & Johnson General Contractors Inc. of Covington, VA, repaired the sinkhole, and it was finished by 9 p.m. the next evening.
The sinkhole was located along the eastbound lanes of I-64 and caused the closure of the right lane and shoulder lane near the intersection of I-64 and Route 834 at the edge of the City of Waynesboro.
The sinkhole measured approximately 18 ft. (54 m) deep. According to Chaz Weaver, VDOT’s Staunton District materials engineer, it was also “roughly 25 ft. in diameter at the top.”
Workers assessed the situation immediately, and repairs started the morning after it was discovered. The hole was excavated and filled, and then the travel lane was paved. Byer, Harmon & Johnson used a Cat 325 excavator to fix the sinkhole as part of its sinkhole and slide repair contract.
A VDOT maintenance contract requires the contractor to be on call and to respond to the situation within three hours.
“It doesn’t mean they have to have equipment there,” Weaver clarified. “They just have to plan the work [within three hours].”
In many instances, contractors have to work around the clock until a job is completed. “Especially on the interstate, we try to get it done ASAP,” Weaver said.
The sinkhole most likely occurred due to a fracture in the limestone deposits that allowed water to seep into the underlying sandstone, thereby diluting it and allowing a hole to form that gradually becomes larger until fixed.
“During abnormally severe rains,” Weaver said, “excessive drainage water passes through the cavity of sinkholes like the one on I-64, scouring the clay at the bottom of the soil dome and undermining its support.”
Since July 2005, VDOT’s Staunton District has had 56 sinkholes, with the vast majority along secondary roads.
“Sinkholes are occurring as we speak,” explained Weaver, “but tend to cause surface damage or collapse during sustained dry or wet weather.” CEG