storm drain % and crown of roads

[jackhewitt]

Im just starting at an excavating co. and would like to know the best way to figure out the % of pitch in a RCP storm drain. I have the two invert elevations and the distance of the run. Also would like to know how to find the crown of a road if I have the edge elevations and the distance frome edge to center. thank you.

 

[buildselection]

1. Subtract the lower invert from the higher invert and divide by the distance.

2.) The center line of road is your crown, meaning you
need the center line road elevations and do the same as above. Usually it's about 2.00% on 50' r/w.

 

[Hoagie]

JackHewit,

Be careful. Although, buildselection is correct for an invert-to-invert calculation, you should check with the engineer-of-record. Sometimes, the engineer will need to match the pipe crowns (not the inverts)in order to capture the HGL.

I hope this helps. Good luck.

H.