Punching Shear At Column with Irregularities?

[Corey7320]

Can anyone suggest a quick way to check punching shear and design shearstud reinforcing at a column with a beam framing into it from one side only, two perpendicular sides only? SAFE gives reactions at the support column, but cannot check punching shear at any column with irregularities in the punching shear zone such as beams, change in slab thickness, etc. Also decons program, which we normally use for shearstud design, does not support these irregularities. On a current job these locations with irregularities are the norm, not the exception, so we would like to avoid costly hand calc methods. Any suggestions?

 

[Bagman2524]

I think more detail needs to be provided.
Is this a slab on grade or suspended slab?
Is the column an edge? or corner column? or central?
Is the beam supporting a slab?
If only 2 sides of the column are supporting the punching shear load I would add the length of these 2 sides + (d/2 x 2) to get your effective length and multiply this by d to get your effective punching shear area. The rest would be the same as if all four sides were contributing to the punching shear strength, I believe its' 4 x .85 x SQRT f'c

 

[youngstructural]

Personally I would not trust a program or procedure that I was not familiar with for a one-off design. My gut instinct here would be to do two (fairly dissimilar) examples of these columns by hand, and afterwords create a spreadsheet which would allow for variations on the theme of the project. This would give you a baseline for the output from your spreadsheet, the ability to get through the job in a reasonable time frame, and also yield a potentially useful tool in the future.

Just my thoughts...

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...