By Margaret Voelzke
Two local bridges are in need of rehabilitation after receiving low scores during a routine inspection.
According to the Virginia Department of Transportation (VDOT), the Interstate 64 bridges over the Maury River and Kerrs Creek scored a four out of nine for structural integrity in a recent engineering study.
A score of four means that the bridges, both nearly 40 years old, are not currently unsafe for drivers, but should be replaced or repaired soon. So VDOT will begin rehabilitating the bridges. The project is scheduled to be advertised this month, and should be completed by summer 2016.
District Bridge Engineer Joe Javier said only one part of the bridges accounted for the low score in the engineering study.
“The rating of four is for the superstructure,” he said, “We rate the bridge in [three] categories… the deck, which is the concrete on top of the structure, the superstructure, which is the steel that holds up the deck, and the supporting structure.”
Javier said the superstructure has deficiencies that include small cracks caused by the stress of traffic and big trucks driving over the bridge. The deck and supporting structures both received scores of six.
The bridges were designed in 1969 and built in 1976. They are called delta frame bridges because their frame resembles an inverted Greek letter delta. Each bridge is 845 feet long and 43 feet wide.
“When [these] bridges were originally built the science was not where it [is] today,” VDOT spokeswoman Sandy Myers said. “Today we would not build a bridge using that format.”
The fissures in the superstructure were found during a routine inspection of the bridge. Inspections take place every six months.
“The cracks and the stress [under the bridge] are not visible [from the road],” Myers said. “You have to actually go under the bridge, and there you can see the cracks.”
The cost of the repairs is estimated at $20.6 million. VDOT says rehabilitating the bridges instead of building new ones will save $20 million.
“The project is out for bid right now, but we won’t have a contract until the end of the year probably,” Myers said. The project’s start date won’t be determined until the contract is awarded.
During repair of the eastbound spans, traffic in both directions will have to share the westbound bridge. During repair of the westbound bridge, traffic will use the eastbound span. That will eliminate one lane in each direction, but traffic will not have to be re-routed from the interstate.
The speed limit will be reduced from 70 to 55 miles per hour during construction. Each span’s closure will probably last about 12 months.
Mohamed Ali, senior engineer and coordinator of the project, thinks inconvenience to drivers will be minimal because of Interstate 64’s relatively low volume of traffic.
“Compared to [Interstate] 81 it is a moderate amount of traffic,” he said.
The Maury River and Kerrs Creek bridges caught the state’s attention because they are considered significant in the Virginia Long-Range Multimodal Transportation plan, called VTRANs2025. VTRANs2025 aims to provide safe, strategic and seamless transportation systems for Virginians.
VDOT says the rehabilitation of the bridges should extend their life by up to 50 years.
“We are breathing new life into [them],” Myers said.
More information, including alerts and travel advisories during the bridge closures can be found here: http://www.virginiadot.org/travel/travel_alerts/staunton/default.asp