irregular concrete canopy

[calculor1]

I've just received sketches from an architect requesting structural drawings for the canopy shown in the attached file. My first thought was to design beams spanning from each of the columns and design cantilevers with torsion. Anybody have any suggestions or comments?

 

[hokie66]

The canopy (the higher level part) itself looks quite stable, supported on 3 columns. May be a 7 to 8" flat plate. But what supports the lower slab over the vestibule?

 

[csd72]

Regardless of how you design it, I would be concerned about the tip deflection at the triangular corners.

FEM analysis may be worthwhile in this case.

csd

 

[calculor1]

I haven't checked the cantilever at the tip yet but I suspect the 10 ft span is okay. If a 6x6 opening is provided in the middle of the slab wouldn't it be better to design beams spanning between columns and design the beams for torsion due to the cantilevers?