poured concrete elliptical arch

[chicopee]

Is rebar needed for a poured concrete elliptical arch having an aspect ratio of two to one? The crown of the arch would be 4" thick to support a pathway. The end of the arch would be supported by an 18" poured concrete retaining wall backed by soil. The major diameter would be about 12' long and minor axis half of that. assume loading at 100lbs per linear ft. Width of arch not yet determine but base you comments on a per width of ft.

 

[dicksewerrat]

How much are the people walking on the path worth? Rebar and 2 more inches of concrete are cheap. why not buy a piece of oval rcp instead. No formwork.

 

[boo1]

loading appears to be low

 

[chicopee]

The live load stated as 100lbs per linear ft s/b 100 lbs per sq ft.
No problem w/ 6" of concrete at the crown of the arch.
I dont want to cut oval RCP in half as it seems like a waste of good material.
Should the reinforcement conform to the shape of the elliptical arch / let's say 2" of concrete conver over the rebar. Also should I provide rebar 2" below the surface of the pathway supported by the arch?

 

[AlohaBob]

Yes. Use Rebar. Unbalanced Loads should produce tension and bending in your arch. Reinforce accordingly.

 

[gbam]

have you considered using structural steel arch culvert? It may be less expensive than concrete.

 

[cvg]

how about trying con-arch? basically steel reinforcing with shotcrete coating.

http://www.con-arch.com/featuresunderpass.htm

 

[ACtrafficengr]

Precast arches are available. I think I just saw something on

http://www.FHWA.dot.gov

about them...

 

[ACtrafficengr]

Found it!

http://www.fhwa.dot.gov/bridge/prefab/index.htm