Hydraulics of safety end sections for highway culverts
BM McEnroe - Transportation research record, 1994 - safetylit.org
BM McEnroe
Transportation research record, 1994•safetylit.orgOn highway reconstruction projects the Kansas Department of Transportation now fits pipe
culverts with end sections designed specifically for collision safety. These safety end
sections are long and narrow with steel bars over the top openings. Scale models of 10
safety end sections were tested in a large water flume in the hydraulics laboratory at the
University of Kansas. The objectives were to determine the relationship between headwater
depth and discharge (the rating curve) under inlet control, the entrance-loss coefficient for …
culverts with end sections designed specifically for collision safety. These safety end
sections are long and narrow with steel bars over the top openings. Scale models of 10
safety end sections were tested in a large water flume in the hydraulics laboratory at the
University of Kansas. The objectives were to determine the relationship between headwater
depth and discharge (the rating curve) under inlet control, the entrance-loss coefficient for …
Abstract
On highway reconstruction projects the Kansas Department of Transportation now fits pipe culverts with end sections designed specifically for collision safety. These safety end sections are long and narrow with steel bars over the top openings. Scale models of 10 safety end sections were tested in a large water flume in the hydraulics laboratory at the University of Kansas. The objectives were to determine the relationship between headwater depth and discharge (the rating curve) under inlet control, the entrance-loss coefficient for full flow, and the susceptibility to blockage by debris for each design. The hydraulic characteristics of the safety end sections compare favorably with those of standard end sections. The inlet-control rating curves are described by a simple dimensionless relationship. Entrance-loss coefficients for full flow range from 0.65 to 0.85. At headwater depths greater than 1.4 times the pipe diameter, a concrete culvert with safety end sections will always flow full. At headwater depths greater than 2.0 times the pipe diameter, a corrugated steel culvert with safety end sections will always flow full. Most safety end sections are not particularly susceptible to blockage by floating debris. Debris seldom obstructs more than about one-fourth of the area of the top opening at high flows.
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