2-way slab punching shear at edge columns
2-way slab punching shear at edge columns
(OP)
I have a 2-way slab and am checking punching shear at the edge columns. The critical section at an edge column typically has 3 sides. How far past the edge face of the column must the slab cantilever before I can consider the punching shear critical section to wrap around all 4 sides of the column? (I can't find anything definitive in ACI 318 nor in the PCA notes that clarifies this.)






RE: 2-way slab punching shear at edge columns
I'd imagine it may be a case-by-case decision (informed by experience and maybe a helpful rule of thumb from one of our wiser members).
RE: 2-way slab punching shear at edge columns
RE: 2-way slab punching shear at edge columns
Some countries have code recommendations for this and some don't. I believe that Canada and Europe both have (or had) recommendations of five times the slab thickness beyond the column face. That said, rapt's method strikes me as eminently rational.
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.
RE: 2-way slab punching shear at edge columns
RE: 2-way slab punching shear at edge columns
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.
RE: 2-way slab punching shear at edge columns
RAM Concept which I've used and ADAPT etc will do this as long as the programs are given proper inputs.
If you're hand-calcing, you need to run it a few ways. Consider not merely the perimeter lengths but also the slab-column moment (ACI 318 Fig R11.11.7.2), which will be somewhat increased by increasing cantilever distance. If you have a lot of conditions, a spreadsheet will be useful. Plus architects are known to shift slab edge dimensions.
RE: 2-way slab punching shear at edge columns
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.
RE: 2-way slab punching shear at edge columns