Punching Shear of slab meeting a lengthy column
Punching Shear of slab meeting a lengthy column
(OP)
My case is as follows
Three floor beams are meeting at a column(225x1000 mm) at one of it's edge as given in the figure attached. I wish to know whether the other end of the column will susceptible to punching failure of the slab and if so how to determine the punching perimeter of that zone
thanks in advance
Three floor beams are meeting at a column(225x1000 mm) at one of it's edge as given in the figure attached. I wish to know whether the other end of the column will susceptible to punching failure of the slab and if so how to determine the punching perimeter of that zone
thanks in advance






RE: Punching Shear of slab meeting a lengthy column
I have yet to see anything in the ACI that addresses this situation.
Decon/Jordahl's punching shear program takes this into account.
http://www.jordahl-group.com/en/1436/service/softw...
Page 11/28 of this attachment has some information as well
http://downloads.halfen.com/catalogues/de/media/ca...
RE: Punching Shear of slab meeting a lengthy column
RE: Punching Shear of slab meeting a lengthy column
RE: Punching Shear of slab meeting a lengthy column
Dik
RE: Punching Shear of slab meeting a lengthy column
Would agree that the Eurocode equations won't necessarily apply to this case when you have beams. Also don't think the 1,000 mm is too lengthy. I can see studrails being an overkill in this situation based on my judgment.
RE: Punching Shear of slab meeting a lengthy column
My guess is that the moment connection between column and slab will take the form of a vertical couple like this:
- The beams providing slab hold down.
- Wads of compression at the nose of the column.
So yeah, my instincts run the same as OP here. I'd go with the Euro provisions because, well.. I'm not sure there is anything else. Some manner of reasonable C-perimeter around the nose. And the integrity bars that dik mentioned. If things do crack up, that should keep ti from getting too far out of hand.
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: Punching Shear of slab meeting a lengthy column
@dik
Are you referring to a one couple of bent up bars over the column or just one couple of bottom bars anchored down to the column. What would be more effective??
@slickdeals
Yes. It is hard to apply Euro codes directly to this situation. Yes it is also true that the length of the column also matters as you can't say at what threshold value of column length would the punching is going to critical.
@KooTK
When working out a reasonable C-perimeter, 2d perimeter distance can be drawn around the nose of the wallumn to the front and sides. But how would it be when it is approaching to the back side(beam side)??
RE: Punching Shear of slab meeting a lengthy column
https://infoscience.epfl.ch/record/200974/files/fi...
http://www.frilo.eu/tl_files/frilo/pdf/en/pdf_doku...
https://ibeton.epfl.ch/MC2010Punching/2011-09-23_M...
Eurocode 2 doesn't specify a distance from the wall tip to consider the control perimeter but the German and Austrian national annexes, as well as MC2010, specify a distance of 1.5*d. An appropriate reduction of the control perimeter length should also be used to take into account load eccentricity. MC2010 does this using a ke reduction coefficient of 0.75.
RE: Punching Shear of slab meeting a lengthy column