Detailing and designing vertically discontinuous slab

Hi to all,

I'm starting as a structural engineer and I came up with a vertically discontinuous slab, meaning that there is a wall that on it's left side is supporting a slab, and on the right side it's supporting another slab, which is about 30 cm below the level of the left side slab. I attach a JPG file.

How can I detail it to provide continuity for the slabs for both flexure and axial (diaphragm)?

I'm currently thinking on forming a tall and wide element in the interface with sufficient width for the flexure rebar to transition diagonally, and also transfer in plane forces as a strut. But I'm not convinced it is the best solution.

Have you ever encountered something similar? Any tips are welcomed.

Best regards.

Here's a good thread on the subject including a strut ant tie model and a recommendation regarding the width of the faux beam at the step: Link. Will you be transferring positive or negative moment at the step? Or both?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

Some common detailing. There are some theoretical holes but it seems to work for situations where moment is distributed.



I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

Dear KootK,

Thanks for your replies!

There are negative moments at the step since the beam that is formed at it is supported by walls.

Thanks for the detailing! if I understand it correctly, for this case the first one applies. What are the theoretical holes?

Regards.

Yup, it would be the top one that applies. The theoretical holes, for me, are:

1) If you ran it through the strut and tie model from the other thread, some things probably wouldn't add up.

2) In north america, we don't seem to subscribe to bar development around corners.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

Actually, both top and bottom reinforcement details above would apply. At least a portion of the bottom reinforcement must be continuous to the support in most design codes.

The details are fine, but I would never consider this type connection as providing full continuity. Maybe 50%. If you need full continuity, the horizontal overlap of the two slab levels should be much greater.