The Progressive Engineer website has an interesting article profiling Colwyn Sayers, a geotechnical engineer with the Lexington, Kentucky office of Stantec. His specialty is inspecting underwater bridge foundations which requires either wetsuit or drysuit diving using topside air sources. Occasionally a hyperbaric chamber is required as well. (Photo credit: Progressive Engineer)
On a typical dive, Sayers looks for signs of deterioration that may cause instability or even collapse of the bridge. This includes scour, undermining from flowing water that erodes the streambed, deterioration, cracks, section loss, and impact and abrasion damage from trees. Tree debris caught in the bridge leads to scour and erosion. “It depends on the construction type as well as the materials on the bridge,” he states.