Three Bar Drilled Pier with Triangular Ties. 1

[RickyTickyTavi]

I just received a rebar submittal for a project I'm working on. I didnt perform the original design but I have been helping review the submittals. The Original Design called for a 12'' dia drilled Pier with 3#5 Vertical Bars and #3 ties @ 10'' O.C. (with extra at the top). The Rebar Submittal for the piers drew the ties around the vertical reinforcement as triangular-- which is something Ive never seen before.

From a confinement standpoint, I'm guessing its fine. I've been looking through ACI315 if there any specifications for circular columns/piers have to have circular ties. In addition, I have concerns that because they chose the triangular ties we'll have too much cover for a portion of the circle.

Anyone have any familiarity with triangular ties on a circle column/pier with 3 bars?

 

[JAE]

A 12" diameter pier, to me, is really a skinny pile....and we've used single bars in the center of our "skinny" auger-cast piling before.

I'm not sure how you'd get a set of 6 bars with circular ties to work in a 12" diameter shaft but maybe it could be done.

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[ProgrammingPE]

I haven't used them, but in Section 10.9.2 of ACI 318-11, it mentions the use of triangular ties when you have 3 longitudinal bars. That would be enough of a blessing for me to be comfortable using them.

http://www.structuralcentral.com

 

[RickyTickyTavi]

Thanks ProgrammingPE.

That code provision makes me feel better.