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The Effects of Channel Transitions on Culvert and Bridge Design. Marla Sykora CE 394K.3. The Problem. Bridges and culverts are designed to allow the passage of natural and storm flows through highway embankments
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The Effects of Channel Transitions on Culvert and Bridge Design Marla Sykora CE 394K.3
The Problem • Bridges and culverts are designed to allow the passage of natural and storm flows through highway embankments • Design criteria are based on allowing passage of critical flows while maintaining a minimum freeboard upstream • Sometimes, the required culvert size and geometry extend beyond the natural width of the channel • Artificial channel transitions are required, and these transitions disturb the natural channel regime • A result of the disturbance may be increased sediment deposition at the structure and decreased hydraulic performance
Project Goals • Demonstrate use of HEC-RAS as a design tool • Compare and contrast sites throughout Texas that exhibit sediment deposition within the culvert system ~ three sites were chosen for this purpose
HEC-RAS as a Design Tool • HEC-RAS was used in the design of a model channel for physical experiments • The channel prototype is a stream located near San Angelo, TX • The design parameters for the model are based on a 1:10 scale ratio • Channel cross-section data were entered based on the research design parameters
Site Locations • Upper Prairie Dog Town Fork Red ~ near Amarillo • Salt Fork Brazos ~ near Lubbock • South Concho ~ near San Angelo
South Concho Watershed • West of San Angelo, Texas • Intersection of US 277 and the South Concho River • USGS Gauging Stations 08127500 and 08128000
Salt Fork Brazos Watershed • Near Lubbock, Texas • Intersection of US 380 and the Brazos River • USGS Gauging Station 08081000
Upper Prairie Dog Town Fork Red Watershed • East of Amarillo, Texas • Intersection of State Highway 270 and Prairie Dog Town Fork • USGS Gauging Station 07297910
Future Work • Comparison of land use / land cover data • Comparison and analysis of gauging station discharge data • Determine if the data indicate consistent patterns from which we could predict when and where sediment deposition will occur