Slab and subtractions

[E-Key]

I create a caisson concrete slab. Floor based family elements were subtracted from slab body. The model looks nice. But! The volume is the same as for solid slab!
Have considerations?

[E-Key]

No comments? I feel alone :(
Designing concrete slab with caissons I have 3 purpose
1. True model
2. True slab volume
3. Calculate a quantity of caissons.

I spent hours trying to get a result but still don't have the full solution.

Any suggestions will be appreciated.

[Dimitri Harvalias]

In order to make this work you need to create the floor as an in place family with the 'floor' category. Once that is done you can place your caissons and schedule floors to get the correct volume.
Maybe someone can explain it better but the problem is that the void is just an object hosted by the floor, it doesn't actually 'interact' with it. Consider the case of a floor hosted lamp on the slab. You wouldn't want the volume of the lamp to be added to the slab.

[aaronrumple]

My preference in this instance is to use a flat slab with the minimal thickness and then add two beam systems to the bottom of the slab. The ribs can then be scheduled. Rather tedious using the join geometry to glue it all together, but then you'll get the correct volume.

[E-Key]

My preference in this instance is to use a flat slab with the minimal thickness and then add two beam systems to the bottom of the slab. The ribs can then be scheduled. Rather tedious using the join geometry to glue it all together, but then you'll get the correct volume.It's a solution too, of course. I can get the volume, but can't have a schedule of "caisson boxes" which make spaces in a slab. My boss wants to have everything in one package. :lol: The real building technology in this case of slab assumes to create a drawing of "caisson boxes" layout.
But it's a really good suggestion. Thank you.

[E-Key]

My preference in this instance is to use a flat slab with the minimal thickness and then add two beam systems to the bottom of the slab. The ribs can then be scheduled. Rather tedious using the join geometry to glue it all together, but then you'll get the correct volume.Great! Thank you!
I made exactly the same, but tried to find floor volume in the properties. I never though that it have the hide volume which I can get with schedule.
Thank you again

[eddy.lermytte]

Ekurbatov

Just a thought

Create the floor as two slabs one on top of the other.
Change the family of the caisson so that the top of the blend = top of the host slab.
Place your caissons in the lower slab.
Join both slabs.

[sbrown]

If you make this as a strutural family I believe it will report correctly.