Minimal Spiral Reinforcing 2

[breaks]

In 8.18.2.2.2, the ratio of spiral reinforcement to total volume of core is defined. Is this ratio referring to the total volume of reinforcing steel to core concrete? The current numbers I'm getting for my specific case seem to be very high and I'm thinking maybe I'm looking at the wording wrong. Any help would be greatly appreciated!

 

[Qshake]

The intention is the ratio of the volume of the spiral reinforcement to the volume of the core measured out to out of the spiral. Mathematically, this is:

rho(s) = (Asp x Lsp)/(Ac x s)

where:

Asp = area of the spiral bar
Lsp = length of one turn of the spiral
Ac = Area of the core
s = pitch of spiral

 

[breaks]

Thanks, Qshake. That's exactly what I was doing. My specific project is in North Carolina, where spiral reinforcement for drilled shafts is specified as #5 bars with a 5" pitch. This overrides the AASHTO criteria and makes my problem moot.

 

[rubedog]

That sounds about right. #5 @ 5,