South Dakota Culvert Inlet Design Coeffecients

Publication: South Dakota Culvert Inlet Design Coefficients (pdf - 1.6 mb)
FHWA-RD-01-076, June 2001

Abstract: Each year, the South Dakota Department of Transportation builds a number of box culverts through its highway construction program. In the past, cast-in-place box culverts were used exclusively; however, use of precast box culverts is becoming a viable option. The cast-in-place culverts feature 30-degree flared wingwalls and a beveled top edge. The precast culverts have a 0-degree flare and a constant 4-in (101.6-mm) bevel (regardless of barrel size) along the top of the wingwalls and the top edge of the culvert entrance.

This report summarizes model testing performed on the above culvert shapes for the purpose of developing design coefficients for both inlet and outlet control. The most efficient configuration tested was the model of the cast-in-place box culvert.