Proper Wingwall Design on Culverts 2

[triathineer]

I am wondering what the proper technique is for designing a concrete wingwall attachment for a sloped pipe. From what I've seen and read, I have encountered 2 ways. One way is a vertical headwall with the entrance/exit slab being flat, and the other way is a vertical headwall with the entrance/exit slab matching the slope of the pipe. Can anyone give me a good direction? Thanks.

 

[cvg]

you do need a posative slope on the apron to avoid standing water. A flatter slope will help to dissipate energy better than a steeper one. Rather than sloped, you may want to step the apron down to match the channel slope. This would keep the flow velocity lower and reduce the amount of scour that will occur at the end of your apron.

 

[gravel]

Haven't really ever seen a sloped apron before. All the pre-cast ones assume a flat exit, even if the incoming pipe is sloped. The actual apron isn't really that long to make much difference anyhow. all that really matters is there is a short cutoff wall, so it doesn't get undermined.

 

[ACtrafficengr]

Is this for a road or site development?

Be careful with vertical headwalls near roads - they are severe roadside hazards. AASHTO recommends that transverse pipes over 3 ft and parallel pipes 2 ft or over have either traversable end sections or guiderail. Traversable ends are preferred.

 

[gbam]

CVG mentioned energy dissapation so I would recomend looking at the outlet velocity to see if "just" an apron is feasible. you may need to design a plunge basin or ?, especially if the runoff is scootin out of the culvert.