Waffle slab depression 1

[Gus14]

I am learning waffle slab design, and I am trying to find ways to simplify the modelling of depressions in waffle slabs. A conservative approach I came up with is to model depression as an opening. Then manually distribute the depressed slab's own weight and the design loads to the edges of the opening in CSI SAFE. What do you think?

I attached a sketch for reference as an example,

https://files.engineering.com/getfi...0-362a-4580-a064-5191ab62f556&file=SKETCH.pdf

Sidenotes;

1. Around the depressed slab, I could increase rib width to account for the increase in required reinforcement.
2. In detailing, I could detail the depression reinforcement as typically done.

 

[Tomfh]

Yes you can mass concrete it like that. Alternatively you can use thinner waffles (say ~150mm thinner in your case), which you extend some distance past the step, to provide a lap zone for the slab mesh.

 

[Gus14]

Thank you tom for replying, this method did not occur to me. It would certainly reduce deflections.