"Doubt about slab support and column alignment in cantilever structure"

[rsantos21]

In this slab, I’m not sure if columns 42 and 41 are supporting the loads from the nearby beams, since it’s clear that the columns are outside the outline of the beams. When this happens, I understand that the column does not support the weight of those beams or the slab. Is that correct?


If so, can I assume that this whole slab is acting as a cantilever and is supported only by columns 23, 22, and 21? And what appear to be beams — could they actually be non-structural ties?

 

[KootK]

When this happens, I understand that the column does not support the weight of those beams or the slab. Is that correct?

I would expect the columns to support the weight of the adjacent slabs until those slabs fail in something like punching shear over the columns. Then the slabs probably cantilever as you suggest.

 

[human909]

As KootK said.

To elaborate slightly, the load will be attracted to the stiffest load path. The columns (even slightly offset) are vastly more stiff than a cantilever slab. Likely by an order of magnitude. So very roughly 90% of the load will go to the columns.

Calculating the exact load distribution reliably is extremely difficult by hand. Computers can help, but you are still dealing with plenty of unknowns. Hence assuming the columns take the full load is a mostly a conservative assumption.

 

[Tomfh]

The beam/slab structure spans to the columns.