This is more of a theory and practice question than a how to question. I'd like to know the forum's opinion on the best method for modeling waffle slabs. Personally I'm not a fan of them and haven't dealt with them in a Revit context before. I'm also not a structural engineer so I don't know if it's better to represent them as a system of floors and joists or just a thick reinforced floor.
There seem to be two methods, subtractive and additive. Subtractive involves modelling with a full depth floor and then cutting the floor with void families to create the empty cells. Additive involves modelling the floor at the thinnest depth and then adding beams or a pan joist system to the underside to create the full system depth.
I currently prefer the subtractive method because it looks more like an actual waffle slab and lets me control both where voids are placed and their shape. I think structural engineers might prefer the additive method however because that better reflects the structural functions of a waffle slab. The additive method however does not replicate the actual appearance of the system which has rounded interior corners in the cells and sections without cells, like near columns or penetrations.
I most often do them as floors as it's easier making openings in it then (using shaft for example) but I'm not an engineer.
I've noticed engineers model it with individual beams but it's a pain to create a big opening in it for us. Means breaking up all the beams etc.
You can create a void family and cut the beams with the void. That way you don't have to break up your beams.
@Avaris. If you cut the structural engineer's beams aren't you defeating the purpose of modeling the structure? Besides, isn't structural modeling their floors around the architectural penetrations? What's the value of a structural model that doesn't account for elevator and mechanical shafts?
Sorry, maybe I was not clear enough. What I tried to say is that engineers don't need to break up the beams, but they can also model a void family. Of course they are responsible for updating the structural model to the need of architects/MEP-engineers.
@kgatzke wrote:@Avaris. If you cut the structural engineer's beams aren't you defeating the purpose of modeling the structure? Besides, isn't structural modeling their floors around the architectural penetrations? What's the value of a structural model that doesn't account for elevator and mechanical shafts?
When we need to model waffle slabs we are often modeling existing conditions in which we are going to make an opening. The structural model is often either non-existent, very late (engineer only brought in in CD) or too simplified to be used in our model (as we render from the model).
omething
@pieter1 You just described my project. Existing conditions, no engineers, unknown phased modifications with probable new floor penetrations. In my mind the ideal solution is that the engineers can somehow model the structure independently of the architectural solids. What I mean is that they model the joists or beams purely as analytical objects without solid masses that coexist with my solid architectural components. That way I can have realistic sections and they can have their analytical model. Is that possible? I don't know because I don't use Revit structurally.
Not sure about whether they can use analytical only, but you could ask them to model certain elements on a specific workset and you can just hide that workset in your model when you link it in (there's a button for it in the manage links dialog). It's definitely not waterproof but works well enough.
We often have structural engineers roughly modeling certain items for calculations (stringers for staircases for example) but we need them to be much more detailed for our drawings/renderings so we model them in greater detail and only temporarily load that part of their file when we need to to coordination.
Hey, I am with the same situation. So, the only method is using the floor/slab Family and Void object? This way the void volume will be subtracted from floor volume (in other words, can I use the floor object volume for order concrete?) the are no chances that can I modeler a parametric slab object family (even if I use Dynamo)? Sorry for the bad english.
Sie finden nicht, was Sie suchen? Fragen Sie die Community oder teilen Sie Ihr Wissen mit anderen.