Punching Shear Checks EC2 with composite metal deck floor

[moyseh]

Hi,

Has anyone come across the case of designing a metal deck composite floor for punching shear before?

My understanding was that you calculate the basic control perimeter, U1 as per the above from EC4 (where dp is the depth to the centroidal axis of the metal sheeting).

I'm a bit confused about calculating the reinforcement ratios. I assume I just work out ρl for each direction taking Asl as the area of tensile steel (bottom steel) per m width in each direction and then bw as 1m and d as the effective depth. Then I use the formula in the bottom snip to get an average?

Any help appreciated

.

 

[rapt]

Are you designing the floor as a flat slab, or one way slab supported by beams? I would have thought it unusual for the decking to be used in a Flat Slab!