headwall footing depth 1

[PSF]

I am designing a concrete headwall for drainage pipe and want to know how far below the riverbed should the footing be? Frost depth is 4'. I would normally think the footing should be at frost depth, but I've seen headwalls that seem to bear right at the surface. Isn't scour also a concern?

 

[bimr]

This was discussed a few weeks ago.

See thread194-315949

http://www.eng-tips.com/viewthread.cfm?qid=315949