Culverts Design - Orifice
A culvert is said to work as an orifice when the upstream water level (HW) meets the condition:
- HW ≥ 1.2 * D
- h = Z1 - Z2
- h ≤ 2 * D
- V = (2 * g * h) ^ 0.5
- Q = C * A * V
- C = 0.62 to 0.63
Onde:
- D - culvert section height
- HW - upstream water level
- Z1 - elevation of NA
- Z2 - elevation of the center of gravity of the culvert section
- C - flow coefficient
- h - hydraulic load
- V - flow speed in the culvert
- A - culvert cross section area
- Q - Flow draining into the culvert
It is said, in this case, that the flow depends on its load upstream, that is, on the
difference in elevation of water levels upstream and downstream, being independent of
roughness of the walls, the length and slope of the culvert.
