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Concrete Pedestal W/ Column Thrust & Tie-Rod

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We have a situation where a pre-eng. steel building column with 46k outward thrust needs a pedestal with the tie-rods placed 2' below the steel base plate (which has a shear lug).  It's a riding hall with no floor.

The footing and pier has been designed for the couple moment, to the point where I was considering the need to hook the pier verts at the top (below the base plate) to develop the bars.  I have not seen this done before, and intuitively, I though that the force between the base plate and the tie rod would be transferred essentially by concrete shear and the horizontal ties.

After looking into MacGregor's chapter on deep beams, and looking at the 2' tie rod offset as a span, the pier, 2'-8" deep, is even deeper than the span.  An extreme case of a deep beam in that light.  MacGregor explains that the force in the pier tension rods would be virtually constant, and states that "...this force must be anchored at the joints."  He goes on to describe design following the Plastic Truss Theory.

Am I on the right track here?  By this reasoning, hooks at the top of the pier are critical.

Regards,

Ed Fasula, EIT


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