Question about HY-8 1

[ENGTitian]

Hi Everybody,
Can anyone help me?
1-what does Outlet and Inlet station mean in HY-8?
2-What is RISE in culvert information?

3-I want to design a culvert with these data, what will be my SPAN & RISE?

Culvert information:
Two 6 by 4 concrete box culvert with no embedment depth/depressed inlet.
Inlet condition: conditional with square edge (0o flare) wingwall.
Manning’ s n: n=0.012
Inlet elevation: EL=92 ft
Inlet station: 0 ft.
Outlet station: 100 ft.
Outlet elevation: EL=90 ft.
Tail water information- Consider the trapezoidal channel:
Bottom width: W=15 ft
Channel slope: S=0.01;
Side slope: H:V=2:1
Manning’s n: n=0.03;
Channel invert elevation: EL=90 ft
Roadway information-Using the constant roadway elevation with paved surface
First roadway station: 0 ft.
Consider the constant crest length: L=90 ft
Crest elevation: EL=112 ft
Roadway topwidth: L’=50 ft


Thanks

 

[Ryb01]

ENGTitian,

You're inlet and outlet station represent the profile stations of your culvert. If these stations are unknown, you could set the stations to your culvert length (i.e.0+00 to 0+015, Length of 15'or 15m depending on your units)

Rise= culvert height. You will need to confirm what the height of your culvert is. Design sheets from the culvert manufacturer will be able to provide. When you say "Two 6 by 4 concrete box culvert", the majority of the time this would mean a span of 6' and a rise of 4'. However, how you orientate the culvert will have a impact on hydraulics.

 

[cvg]

n value for a box culvert will not be 0.012, probably more like 0.015