One-Way Flat Plate Punching Shear
One-Way Flat Plate Punching Shear
(OP)
Can anyone guide me to an example calculation for punching shear through a one-way flat plate slab?
The popular "direct design" method is well enough documented, but what about if the slab isn't 2-way and doesn't have more than 3 bays in either direction? Is there a documented way of going about such a calculation? All the examples I have seen say that if the flat plate doesn't meet the requirements for using the Direct Design Method then more stringent analysis must be used - However, in all my searches I have never seen an example.
Is the calculation exactly the same as punching shear through a pad footing, except that the shear force is multiplied by certain factors to account for moment transfer from slab to columns?
Right now I am being forced to use the British method (which seems quite simple enough), only that I cannot justify it by anything I have found within ACI or CRSI.
Can anyone help? Thank you kindly.
The popular "direct design" method is well enough documented, but what about if the slab isn't 2-way and doesn't have more than 3 bays in either direction? Is there a documented way of going about such a calculation? All the examples I have seen say that if the flat plate doesn't meet the requirements for using the Direct Design Method then more stringent analysis must be used - However, in all my searches I have never seen an example.
Is the calculation exactly the same as punching shear through a pad footing, except that the shear force is multiplied by certain factors to account for moment transfer from slab to columns?
Right now I am being forced to use the British method (which seems quite simple enough), only that I cannot justify it by anything I have found within ACI or CRSI.
Can anyone help? Thank you kindly.






RE: One-Way Flat Plate Punching Shear
You're right that you have to account for moment transfer but it's not by putting factors on the shear - look at 11.12.6.2 and the commentary for that section. You can probably find a worked example in a concrete textbook.
RE: One-Way Flat Plate Punching Shear
RE: One-Way Flat Plate Punching Shear
In your university days surely you were taught methods of analysis that will allow you to calculate more accurately the actual moments/shears/reactions in the member you are designing.
Punching shear calculations then check the effects of these actions on the member you are designing.