NORFOLK – VDOT, the state agency overseeing Virginia’s roadways, is now using new technology to check work under water.
Side-scan sonar lets engineers gather data at around 300 feet, not only straight down but from side-to-side. It produces 3-D color contour maps, sonar images and show elevations of the river bottom.
Recently, 13News went along as engineer Jeff Blevins went out on the Elizabeth River. He’s one of the first to be trained to use it.
“It was pretty advanced technology and it took a while to really gain the experience and knowledge needed," said Blevins.
Data on the screen tells Jeff Blevins about scour, which is deterioation that is created from sediment that builds up on pilings underwater. VDOT says that sediment could weaken structures underwater.
The technology also lets VDOT check construction projects at bridges and tunnels to ensure that contractors are doing the work they’ve been paid to do.
VDOT engineers check beneath the surface at every major tunnel and bridge and 19 waterways about once a year.
The agency has had side-scan sonar for about two years, but it’s only been in routine use for a few months. Crews have used the technology in Southwest Virginia, on the Eastern Shore and in Hampton Roads.
