multiple structural models - one buliding

[david_peterson]

I've been trying to figure out if it's possible to split a building into multiple models.
Not that I really want to do that but I'm looking at one building that's going to be about 1.6million sqft. I'm not sure if Revit can even handle that, much less my workstation.

So I created a couple of simple little models and linked them together. What I found was a little disturbing. Unless I'm missing something.
It would seem that foundations, footings, foundation walls.... will not join.
You also can't frame from a column in one model to a column in another.
Now I know where I have dedicated expansion joints with no connection between the super structures I can split them if needed. But I'm not sure what to do with the foundation.

So how would you proceed?
I'm thinking that I may put the entire foundation in one model and the framing for each area that's defined by an expansion joint in additional models.
My other thought was to see how big of a file Revit can handle and try to beg my IT department for one heck of a workstation.

Any ideas or concepts would be great.
Thanks in advance.

[FOUTJM]

i think your only choice is to break it where things do not need to connect.

[Steve_Stafford]

SF isn't the issue, it's the complexity or quantity of elements. Fwiw, RST project files are usually about a third of the size a RAC file is.

I'd plan on a single file first and use worksets to manage how much is loaded into memory at one time. If you must break it apart then do it at expansion joints, somewhere the building logically "separates" as mentioned before.

[david_peterson]

Thanks Steve.
But now I've got a little more information I'm wondering if that would change your mind.
The project so far has been split into at least 18 different (9 for foundations and 9 for steel), unique phases based on construction sequence. So each phase will required it's own package with it's own unique details. Anything in the future or past will need to be screened. Also I may be issuing a foundation package at one end and a steel package at the other end on the same day.
Each package is to be considered a different & separate contracts (one for each contractor on site). I believe they are looking at working on 3 different areas at one time so I'm thinking I'll have at least 6 generals on site at once just for structure.
So knowing that, would that change your mind on trying to use one model? Have you or anyone else ever heard of trying to do a project with that many phases?
Thanks in advance.

[Steve_Stafford]

It could be done with a single file still but you'd have to be careful to create all the phases you need and then assign elements to the correct phase. Each contractual deliverable would print from the "New Construction" phase for each unique scope. The advantage of a single model is that all the detailing could be shared. You'd still need to keep the sheet naming unique so it could be printed from any phase but still appear in the "set". You'd have to have different sets of parameters to manage sheet title block information correct for each deliverable.

That said, it may be a good idea to approach each contractual deliverable as a separate project file. That is in keeping with Revitology, that a project is a "building" unto itself. The fact that all of these structural projects might ultimately be one "building" is secondary to the fact that everything you put in one model is meant to stand-alone...as if the other work never happens and the skeleton sits waiting for rust and time to do its thing.

Separate files will create issues for shared details but solutions for that are described in numerous posts here as well as similar to what I describe being necessary even if you do all the work in a single model but deliver it in phases. Separate files will also make it much harder to do analysis on the whole building. You may have to do a series of analysis runs where you put all the buildings together in one file as links > Bind > Ungroup and run analysis. If each project can have its own analysis run separately and still prove the design is sound then that makes it all that much easier.

Either approach will have idiosyncratic things to work through...which one is "easiest"...you'll have to tell me after you guys do one or the other. ;)

[scowsert]

Revit certainly could do it all in one file as noted. Now the question is how good are you and your crew at dealing with the different phases. It isn't difficult but man... that's a big project for one guy to oversee the whole thing. It might be easier for your crew to do the seperate model approach and link them all into each other? Then again theres the trickyness there. Ok which model do I print from? Vs one mega model. Steves point on Analysis is a good one too. Will you guys do that? If not then that simplifies things.

Somethings to help decide. Will the project and each building each have their own unique sheet numbering aka... If the whole set was printed and stapled together there would only be one S1. If so then you could build it as one model. If each print will get different S1's then you'll fight revit the whole way through and I'd go the linked route.

But like Steve says there really isn't one right answer only different ones each with their own benefits.

Would you rather manage seperate files each with their own phases, or one mega file with different sheetsets and phases? How is the architect approaching this?

[david_peterson]

Nope not going to use it for any analysis. No need to worry there.
The idea we came up with so we don't get confused with phases (plus I'm not sure if revit can do an option for New w/ "existing" and "future"). So we looking at creating a parameter or filling one in for phase on object and using filters to get them to display correctly. It's my co-workers idea. He's looking in it. Now sure if that's a great idea either.

As for common details, no need to worry. I'm sure I'll develop them as far as I can, but I don't think I'll be able to use the exact same details in different phases/projects, but I can copy them. We'll end up with completely independent sheets/views for each. I don't think I'll be able to modify drawings that could affect the next phase. I've run into this before. There's going to be a point in time where I have one set of drawings out for Bid (at which point I can't touch them) while I'm issuing CB's for another. There's going to be a Spine to the building that connects all the other buildings. It's going to have combined foundations. It's going to be ugly.

As for my archie's they've gone with the multiple model idea. I think they are looking at splitting it up into (I believe) 23 different models. They were going to do one for the exterior (which isn't going to be very complex). It was going to include the "Core" elements such as stairs and elevators. That was the only thing that seemed wrong to me. Since the stairs and elevators really have a bigger relationship to the individual spaces and no relationship to the exterior. Either way they get an extra 4mths to figure stuff out. Which tells me changes are going to be plenty. But the upside is that my concrete is going to be existing at that point and last time I checked it's really hard to erase them after you pour them.

If anyone has any additional advice I'm listening.
I'll report back from time to time.
Thanks in advance.

[Steve_Stafford]

I don't think I'd create my own phasing process but have fun! For future work I usually just overlay views on sheets and manage the visibility and phase/phase filter settings so it only shows the future phase work. It just depends on how much detail is really need to convey future features in previous views. I wrote about this approach on my blog (http://revitoped.blogspot.com/2007/01/future-phases.html) in October 2007.

[david_peterson]

We just got done looking at it, and it's a slick little process. Create a project parameter for each phase. Assign each element to that phase. Create a view filter to screen everything that isn't on the current phase for that view. Works on just about everything but annotation items. The idea (hope) is that we can issue the same sheet for both a foundation package and a steel package, so you need a way to show that detail different for each package. (What's screened in one is bold in the other) Create a view template with that view filter, and apply it to all views to switch from one package to the next. Still not sure I like the idea, but hey what's the worst that can happen? Oh wait, worst would be to have to have 2 details for the same thing. But I'm sure I'll have that anyway.
Thanks for all the input.

[scowsert]

I don't think I'd create my own phasing process but have fun! For future work I usually just overlay views on sheets and manage the visibility and phase/phase filter settings so it only show the future phase work. It just depends on how much detail is really need to convey future features in previous views. I wrote about this approach on my blog (http://revitoped.blogspot.com/2007/01/future-phases.html) in October 2007.

Cool. I read the first part and said to myself... what is he talking about? Revit only looks backwards not forwards! Then click on your link to your blog post. Oh awesome! Nice little hack there. I like it. :D