Supplementary Tensile Reinf. (Condition "A")

[ReverenceEng]

I have a flagpole with a pretty deep cast-in place pier andrebar cage, using thick plate with about 16 Anchor rods. (130' high pole)

My question is, can the long reinforcement that is already in place for flexure be also considered assupplementary tensile reinforcement and allow me to use condition "A" for the anchor rods and ignore tensile breakout (Of course I have ensured there is enough development length on both ends of the breakout cone and lap length between the bolts and rebar)? I am using 16 # 7's on about a 42" circle and I have 16 1-1/4 Anchors on a 30" circle, so there isn't a lot more room for additional rebar...

 

[KootK]

Yes, sort of. I think that most folks would abandon the appendix D stuff for this and take a reinforced concrete approach wherein the anchor rods effectively passed their tension to the rebar cage via struts and ties, non-contact lap splicing, or methodology similar to that used for base plates in AISC design guide #1 (failure frustum with developed bars crossing the boundary). That said, if you can follow all of the APP D rules and make a go of it, I think that's a valid approach too, even if that stuff was developed with shallow anchors in mind.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[ReverenceEng]

thanks koot!