Cutting walls with steel structure ?

[MKEllis]

Hi,

I'm placing a steel frame within a school building.

Is there a way to auto-cut the walls where steel UC/UB sections are added ? See attached image (In plan and section).

I'm aware of that I can use PARTS to break the detail down in the detail call-out which will 'correct' the detail. I'm after a way that will update the whole model.

The other method that I was thinking of - which would work more effectively in section than plan - is to create another wall type for the beam level - that has 2 layers of sounbloc board + insulation, with an air gap in the structural zone. This would then be placed to subdivide the main wall where needed. That would enable the plasterboard / insulation to be quantified. This will be a bit fiddly to do across the large model though.

I guess my query is - how far do you guys go to reflect the 'reality' in the model. I'm not necessarily talking about the detail level, more a case of having the geometry operating in the way that it should ? Would you generally let that detail remain as is in the model - and simply correct it in each detail view ?

From my side at the moment - this is the first larger project that I'm doing with Revit, and it is throwing up a large number of queries (of which I'l be posting more soon especially around how to manage linked files via 360). When I was teaching myself on small scale tutorial projects it is easier to adapt the geometry as you go. Obviously as the project gets larger it becomes less and less efficient to 'correct' the model wherever a particular junction occurs - unless Revit can be persuaded to do so automatically.

Thanks

Martin

[Alfredo_Medina]

I think that in a large project, those conditions should be shown at the details, only. It might be time consuming and cumbersome to have all the columns and beams cut the walls in plan and elevation all the time, especially considering that for a large project you need to deal with constant changes in the structure, which usually come from another professional who will be sending you his drawings or Revit models, with constant revisions.

There is no automatic way to cut the CMU in that way with the steel and beam columns. One workaround is to put a masking region in the steel families, as shown in the attached image. Another workaround is to use separate wall elements for the components of the wall, instead of compound wall types. Both of these solutions might be time consuming.

Again, you need to measure what is more efficient in terms of time spent versus actual benefit. Details only or model? Details only is my recommendation.

[constantin.stroescu]

I am against  overmodeling in 3d . I think that it is important to keep the file in an  acceptable size.. I use 3d only for major forms and I develop the project in 2d.....

The problem with the inserted structural steel columns or beams into the wall is that Revit has , in my opinion, some inconsistencies...sometimes appears correct , sometimes not...and I could not find the cause of this..(maybe because two surfaces overlaped.)...

Speaking now about workarounds (in addition to  what Alfredo says) , I observed that if overriden the patern of the steel beam to Solid Fill and using the Wireframe Visual Style this inconsistence ceased to manifest.. but  the depth of the section has to be drastically limitated..

[rosskirby]

*Edit: meant to reply to the OP, not Alfredo.

Are you modeling the structure yourself, or is a structural engineer providing a Revit structural model?  If the structural model is coming from a 3rd party, then I'd say follow what Alfredo and Constantin have suggested, as that is the most widely accepted and supported method.

However, if you're a glutton for punishment, or for some reason are modeling the structure yourself, there might be a way.  Take your steel column family, and load it into a new generic wall-hosted family.  Align/lock it to be centered on the wall, then create a void with instance parameters centered on the nested column family.  Make the void cut the wall.  Voila!  You've got a column family that cuts the wall.  

Now, before you get too excited, there are going to be some drawbacks. Wouldn't be much of a workaround without drawbacks, would it?  Then we'd have to call it a solution.  So, here are some of the drawbacks.  You're going to have to do some legwork to get the void family tied to the outside reference planes of the column family, but it's definitely possible.  You'll also have to assign the column family to a Family selector parameter (whether you choose type or instance is up to you, depending on how many different types of columns you're going to have) so that you can use the same family for multiple column sizes.  And every time you need to incorporate a different column size, you're going to have to import the new size via the type catalog for the column family, then swap out the type via the Family selector parameter you established earlier.

Jeez, that turned into a novel.  Anyway, it should work, but is it worth it?  Not in my opinion, especially if any of your column lines are eccentric from the wall center, or if you've got more than 10-12 different column sizes, but you could add an offset parameter for the eccentric columns, so it's still workable.

Good luck!

[MKEllis]

Thanks for all the advice - I'll try each of those methods (even if I don't end up using them, they are great for learning the foibles of Revit). On the face of it, it seems that the 2d suggestion is far more efficient, but it does throw up a more general query.

How useful is the model in Revit in quantifying ? with these work-arounds it seems to me that the areas, volumes and quantities are likely to be inaccurate (obviously in some cases only be small margins - the amount of block cut by the steel is v. low %). How is that managed in practice ? in a real project environment do quantity surveyors rely on interogating the model to provide measurements through something like Navis Manage ? I fully understand that the level of detail should really be driven by what is useful and not necessarily just what looks good - but from my perspective at the moment with very limited real project experience it is difficult to know where the line is drawn.

Many thanks

Martin