Note to Revit: Please quit anticipating my needs [columns, beams, and as-built nightmare]

[steve922542]

A couple of weeks ago I posted about problems I was having using RA for as-built conditions. Specifically walls that are not parallel. We all know squares are not built square. I got past that hurdle. Now...

I am completely stumped how to proceed 'correctly' trying to model conc. columns, beams, and slabs. Revit keeps 'helping' me by joining the beams, limiting small tweaks to parallel or in-line with other beams, rejoining with columns with beams that I have un-joined, making crazy joins that go way out of the model, etc.

It is a nightmare. The result is that I have a terrible model which is only an approximation of the as-built survey provided (read less accurate). The reason I pushed to use Revit is so that we can cut true sections and provide a model to the interior designers who have tight spaces with low overheads to deal with.

I can think of some work-arounds but I can only imagine the problems that they might introduce. I do not think it is possible to create this model using the structural tools provided. I can't use grids. Even reference planes for every object won't work because of the ridiculous automatic joins. I tried drawing all the beams first on an overlay, but adding the columns afterward gummed it up as well.

I could model the whole thing in AutoCAD much easier. In 3D studio it would not be that difficult either. It would be easy to model new construction too but for these renovations or as-built drawings, I feel like I'm using a jeep in formula 1- or a formula 1 car at Moab for those Reviteers that prefer that analogy.

Any advice, suggestions, jokes, or consolation is appreciated. Until then, I will (sadly) be working in AutoCAD and (perhaps misguidedly) wishing I had ADT.

And since it will affect the advice given:

1. client is the contractor & developer
2. renovation (major) of existing 16 story building built in the 1940's (all concrete)
3. new structural as-builts accurate to 1/4" in CAD show columns and beams for each floor (and they do not line up exactly vertically so every floor is different)
4. currently working to reconcile as-built conditions with archs/IDs (output to arch for redesign)

One floor of the survey is attached for the curious.

[SkiSouth]

Here's what I'd do. First, stay with Acad for a minute. Be sure all the exterior wall, the "x" markings of the columns etc are on differing layers. Save drawing. Start project, import dwg file. Edit import, deleting non essential layers. (IE. keep columns). Explode dwg. Window all lines, with copy to clipboard. Start new extrusion, and paste lines into project as column category. Suffer through the finding of all overlapping lines, non closing etc, finish family with column height. Now have one big column (existing phase) for all vertical supports. Repeat process for beams. Add floors and openings. Then exterior walls and sun shades/overhangs.
Hardest thing is being patient in finding the overlapping and stray autocad lines. Use Entity ID for that.

Then put on your documents columns/beams based on information furnished by x on sheet y. Verify in field - or some such - this example took about 20 minutes total.

[truevis]

I concur with Skisouth -- in-place wall & column families.

I'd say don't explode DWG, use Pick Lines/Tab to trace; but maybe his way is better. Maybe use Overkill and clean up in ACAD first.

If you use regular walls, keep disallowing joins at endpoints then can use Join Geometry but it will still probably do plenty of unwanted behavior. Walls off of each other by a few degrees are tough.

O for the switch someday to turn off automatic relationships in Revit -- really my only wish list item.:shock:

I modelled a 750000SF similar project last summer.

[steve922542]

Thanks guys. Although I know I shouldn't let it, I continue to find Revit's shortfalls very discouraging. Unfortunately I am at the point where I could not recommend the software to a colleague that did anything but the most common of commercial buildings.

My expectations are not outrageous - not looking for a silver bullet.

[steve922542]

BTW - can't justify spending anymore time on it. It's going to revert to a 'drafting' exercise which is what the client asked for. A real shame.

[SkiSouth]

too bad. I think revit would have served your needs better.

[rkitect]

Steve,

It's hard to say exactly what to do without seeing what behavior you're wrestling with, but I can guarantee you that it is possible as I've done several As-built projects in similar situations. Stick with it and play around in the menus and especially the Keyboardshortcuts.txt file and you'll learn some shortcuts.

One to note especially here is the 'SO' or Snaps Off shortcut. This will turn all snap relationships off while moving/copying/rotating/etc/etc/etc an element.

As far as automatically connecting beams, I'm not sure I can help you there without seeing what is happening. I downloaded your columns, which is interesting in itself but could not mimic the auto-connecting beams behavior :\

Let me know if I can help any further.

[steve922542]

too bad. I think revit would have served your needs better.

Long term, absolutely. This week, far too many unbillable hours on what should be a simple exercise.

Rest assured, I'll be back at it, and I'll post the best solution I can come up with. I think a combination of the in place column method and then a custom family that looks like a beam but stays put around the columns will do it. The wall method for the beams is intriguing but since I have as-built slab to bottom of beam heights that I need to model, I need an 'beam depth' instance parameter for each beam segment.

You'll be happy to know that I did not spend my time in ACAD mindlessly clicking and offsetting. I made a beam label block with attribute information and used data extraction to create a beam and column schedule as well as exporting to client's system.

[SkiSouth]

I too have fallen back to Acad when a site must be done. There are tools that you must go to when the clock is ticking. Completely understand. Glad you're still on board with Revit. Its the first software in years that has actually helped my bottom line. ADT use to KILL me every 4-6 months with a new UI and commands etc. Re-learn each release sucked.

[steve922542]

Steve,
As far as automatically connecting beams, I'm not sure I can help you there without seeing what is happening. I downloaded your columns, which is interesting in itself but could not mimic the auto-connecting beams behavior :\


Once I catch up on my work and settle back into it, I'll post some very concise 'simple' challenges. But for a preview, it will probably just be the lower left hand corner of the drawing that has 9 columns around one bay. Try plopping some structural columns in, aligning them to the overlay and using the beam object to match the CAD drawing. It's easy to get 95% accurate, but exactly what is shown does not make Revit happy.

Thanks again for all of the suggestions, and I hope that there will be a ultimate victory with it, but it's going to be on my dime.

[sjsl]

Sounds to me like you have lousy acad backgournds and the user who put them in (if its you I am sorry ). We stopped using acad backgounrds from other than our own staff and sometimes we don't use them for anything but a ref. They are never drafted very well and always have way to many lines slightly off axis. That's ournightmare.

[truevis]

Sounds to me like you have lousy acad backgournds and the user who put them in (if its you I am sorry ). We stopped using acad backgounrds from other than our own staff and sometimes we don't use them for anything but a ref. They are never drafted very well and always have way to many lines slightly off axis. That's ournightmare.

An accurate CAD survey of an existing building may have many lines drawn slightly off axis. If we want to model to existing wall conditions which actually are slightly off axis in Revit, that's where our trouble starts.

[tomnewsom]

Agreed. I'm battling many of the same problems as you.

At first, I used lots of in-place custom families, Picked from the survey lines, but this is a useless approach if you're going to do any demolition work.

I now have a load of 'extg' wall types, 100,125,150,200,250,300,250mm etc. thick, which I use to build all walls, columns (rectangular ones anyway) and beams. I use pick and snaps to the imported survey drawing to line things up. I use lots of 'Disallow Join' and lots of forced snaps (eg typing SE to snap to ends)

This does result in some walls which are a litte fatter or thinner than the survey, but I try to keep it within the accuracy that can be expected from a survey of an existing building.

It's more labour intensive than custom families, but the end result is faster to work with in terms of selecting items and editing the extg model. It's especially good for demolitions though - you can use the split and demo tools to accurately remove parts.

I have generic 'extg' doors, which are simple openings with line representations of the swings, in a fairly wide selection of sizes.