Punching shear at column face - flat plates

[drapes44]

When carrying out a punching shear check for a flat plate, is it necessary to check for punching shear around the column face, or is it enough to check at a distance of d/2 from the column face? Believe AS3600 and ACI318 have no such requirements, but EC2 does. Understand it covers the case where you get crushing failure around the column face by a compressive strut, but unsure why this requirement has not been adopted in AS3600 or ACI318

 

[serrojo]

Got your point, every code depends on the scientific data (from destructive tests and other) so every code establishes requirements due to the phenomena observed, legally speaking: you should just comply with the current code. Scientifically speaking: you can simulate plate-column interaction with ABAQUS or similar, than calibrate with actual test data, than study the behavior of that joint and make your own conclusions.

Regards

MSc. Eng. Serguei Joa
Structural Engineer
Bouygues Batiment International, Cuba.

 

[KootK]

Can you post the EC2 provision? Or at least provide the document title and clause number for we non-Europeans? In ACI 318, there is a provision limiting the maximum shear stress that can be used regardless of the degree of shear reinforcement. I believe that is how the crushing failure of the struts emanating fron the column is prevented in that code.

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.

 

[drapes44]

KootK,

In EC2, clause 6.4.1(4) states that the shear resistance should be checked at the face of the column and at the basic control perimeter u1. Also, clause 6.4.5(3) states that adjacent to the column the punching shear resistance should be limited to a maximum of...

Although there is a provision in ACI318 limiting the max shear stress, the calculation is not based on the perimeter around the column face, but rather around the critical perimeter defined as being d/2 away from the column face: for two-way action, each of the critical sections to be investigated shall be located so that its perimeter bo is a minimum but need not approach closer than d/2

AS3600 is in fact my baby, which like ACI318, appears to have no specific provision for limiting the max shear stress at the column face. But it has puzzled me as to why EC2 and even BS8110 accounted for it. I suppose it may be as simple as serrojo suggested