Concrete Truss
Concrete Truss
(OP)
I am evaluating a column transfer condition by another engineer that I am equating to a concrete truss. I am simplifying the condition for this post, the shape is essentially shown below, with both the top and bottom chords reinforced and confined with column ties. The panels(all three) are poured solid and reinforced with vertical and horizontal steel, no angled webs in the middle panel. Two columns are transferred out at quarter points. The span is about 60ft and the depth is 14ft. The span to depth ratio does not fall under the strut and tie rules.
I have some other concerns, but my question is do I have a shear problem at the supports? If it acts like a truss I don't. But as a beam with tapered ends shear is not even close.
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I have some other concerns, but my question is do I have a shear problem at the supports? If it acts like a truss I don't. But as a beam with tapered ends shear is not even close.
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RE: Concrete Truss
RE: Concrete Truss
However, going back to shear, the limits set in ACI 11.7.3 (10 (f'c)^1/2 x bw x d are not met. This could be resolved by not tapering the ends, there is room to do this.
I know that a truss was modeled using software, and that the chord members were checked for their respective axial loads. With the tapered ends both beam shear and deep beam shear do not work. So for this model to work, it has to act like a truss.
RE: Concrete Truss
To act like a truss, you will need to design the joints and members for shear also.
How are the truss bearing joints being modeled for the shear?
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Concrete Truss
RE: Concrete Truss
RE: Concrete Truss
ACI A4.3 allows among other things standard hooks and even straight bar development as acceptable ways to anchor ties, as long as they are developed past the "extended nodal zone" which is pretty well defined in the code as well.
RE: Concrete Truss
RE: Concrete Truss