Question

A a = 0.55 (m) × b = 0.3 (m) concrete box with Manning roughness coefficient of n = 0.016 is to be placed under a roadway. During the T = 100 years design storm, it is expected that water will pond behind the culvert to a height h = 0.2 (m) above the crown of the culvert. If the culvert entrance is to be rounded with the exit loss coefficient of Ke = 0.2 and discharge coefficient of Cd = 0.45. If the slope of the culvert is S% = 0.2 and the length of the culvert is L = 4 (m),

1. estimate the flow rate through the culvert.
2. If the flow rate drops down to 20% of the design storm, estimate the depth of water behind the culvert.

Answer 1