Effects of Inlet Geometry on Hydraulic Performance of Box Culverts

2006Jones, J. SterlingDistribution number: HRDI-07/12-06(WEB)EPDFTech ReportFHWA-HRT-06-138DTFH61-04-C-00037Culvert inletsBox culvertsUnited StatesUnited States. Federal Highway Administration. Office of Infrastructure Research and DevelopmentJones, J. SterlingKerenyi, KornelStein, StuartGKY & AssociatesUnited States. Federal Highway Administration. Office of Infrastructure Research and DevelopmentSouth Dakota. Department of Transportation. Office of ResearchTurner-Fairbank Highway Research CenterFederal Highway AdministrationEach year, the South Dakota Department of Transportation (SDDOT) designs and builds many cast-in-place (CIP), or field cast, and precast box culvert structures that allow drainage to pass under roadways. The CIP boxes typically have 30-degree-flared wingwalls, and the precast have straight wingwalls with 10.16-centimeter (cm) (4-inch) bevels on the inside edges of the wingwalls and top slab. Previous research conducted on a limited number of single barrel box culverts indicated that further research was necessary to determine (1) the effects of multiple barrel structures, (2) loss coefficients of unsubmerged outlets, and (3) the effects of 30.48-cm (12-inch) corner fillets versus 15.24-cm (6-inch) corner fillets. In order to optimize the design of both types of box culverts, it was also necessary to determine the effects of span-to-rise ratios, skewed end conditions, and optimum edge conditions on typical box culvert installations.73