Collins recently completed Level I load ratings for Virginia Department of Transportation of the Route 33 bridges over the Mattaponi River (Lord Delaware) and the Pamunkey River (Eltham) within the Fredericksburg District. The team was led by Collins’ Virginia Beach, VA, office, in collaboration with the load rating experts from the Norwood, MA, and Chicago, IL, offices. The Lord Delaware Bridge consists of 32 post-tensioned, prestressed bulb-tee spans with a structure length of 3,545 feet. The Eltham Bridge consists of 49 post tensioned, prestressed bulb-tee spans and one double leaf trunnion, bascule span with a structure length of 5,354 feet.
Each load rating included “as-inspected” condition factors, dead loads not captured previously, and a more accurate representation of the as-built bascule structure than previously modeled. The prestressed concrete bulb tee spans were modeled in AASHTOWare BrR, the post tensioned spliced prestressed concrete bulb tee spans were modeled in BridgeLink PGSplice, and the double leaf trunnion bascule span was modeled as a girder floorbeam stringer system in AASHTOWare BrR and STAAD Pro.