Column Grid Xref

[dhallett]

Is there a way to attach structural column members to an Xref'd column grid? I thought it was smart to set up the building structural grid as an element that is attached to each floor level construct, but now I can't use it to attach columns. Thanks for any help!

[Steve_Bennett]

The column grid should not be xrefd if you are using constructs/elements. It should be created as a construct since it would remain the same throughout the building levels. Elements are more for unique objects that are not repeated throughout the building. Using the grid as a construct should allow you full use of its wonderful features.

[dkoch]

It is the opposite. Elements should be used for building parts that are repeated [such as a building core layout, which could be the same on multiple floors]. Constructs represent the conditions for a specific location - such as the Third Floor - and may include Elements, such as that core.

Items in an Element do not have a location in the Building Model until they are included in a Construct. When tagging in a view, ADT places the property data at the Construct level, so that multiple uses of the same element on different floors can have unique property data - such as a door number.

All that said, you can not anchor structural members to a grid through an XREF, so you either need to live with unanchored columns or put the grids into a Construct. [Or put the columns in the element, but I assume you want to be able to vary the column sizes from floor to floor.]

[dhallett]

Thanks for the comments. I did try putting the columns in the element drawing, but of course, they showed up at every level and my composite model had columns sticking out of the roof! I’ll keep the grid as an element, and just put columns in the plan constructs without attaching them. I like the consistency of using the same grid in all plans.

[david_peterson]

The way I've done our column grid was to create one construct for the grid for the entire building. If you need to add columns or subtract columns you can accomplish this by either adjusting the cut plans and or adjusting the start/end off sets.
If you need a col that's going to be 50' tall when it shows up to the job site, drawing it 50' tall. If you have a col that starts at the 2nd floor, adjust the start off set.
If you have a column splice you can either create a custom struct member or you can simple add the col on top, again adjusting the start/end offset.

[tatriest]

David, I prefer to draw the columns on the Column Grid construct for anchoring purposes. But, when you do have a splice, how do you not show both columns in plan view? I could not find any cut plane adjustments that would handle this.

Terry

[david_peterson]

I've done it both ways.
One, create a member style with 2 profiles, 1 for each size, and draw it as a continuous col. with in the style, set the end point for the 1st shape @ the splice location. Set up the construct as belonging to all levels, and set the appropriate elevation. When you create your view, the default is to have the cut plane set 3'-6" above the floor. Depending on where you place your splice (3'-0" above floor) you should see both shapes. Adjusting the down field cut plane will allow you to not see the other shape.
The other option is to draw grid files for each floor and with cols both above and below. Then you can adjust the style to change it's display.
Here's a question back, what are you trying to get out of your model by adding all the extra work? Opps maybe I assumed to much and you're doing a CIP structure. Then I can see the benefit.

[tatriest]

I am trying to have it so the columns are anchored to the Grid. It would be nice to have 1 Grid for the entire structure...I also thought it would be less work with the column as one piece......

WELL, you asked a very good question....."what are you trying to get out of your model"....... now, as I reflect on that, I am thinking that it would be better for each floor to have its own Grid -- because there may be additional/fewer columns on some levels.

This evening, I am preparing for a presentation on Project Navigator for tomorrow noon. I will tailor the sample project for individual Column Grids. Wish me luck.

Thanks for your input.

[cholmes]

Just to add some comments, the way I approach column grids is this - there is a main column grid which contains all of the main columns that appear on every floor. Then, if a floor has some additional columns, I will create an additional grid that contains just those additional grids and columns, which then can be xref'd into just that floor (so two grids would be referenced, the main and the additional)
Another option, have one grid file, and have the additional grids in that same drawing, just on different layers that can be frozen or thawed as req'd in each floor.
In most cases I only have the main grid. Also, since I am in a multi discipline office, the arch, elec, and mech can all reference the grid as well, which helps keep everyone coordinated.

[jastect]

I'm trying to figure out how to set things up right when I finally start using PN. I had the same grid problems as dhallett. I ended up with several grids because of the xref problem. Almost every floor has different column sizes. I also wanted the correct sizes to show with the spray-on fireproofing for plan detailing. I'm not that concerned about columns showing in the model (except for the two-story lobby), but it would be nice to show the clients and principals a working model. I guess the columns would be nice, actually, for showing our parking garage floors with it's double helix. (Now who can tell me how to draw that?!)
I'm confused about the one construct with all columns. Is it worth it for 16 stories? Probably not. How do you set up the cut planes to show only the relevant columns on each floor? If you set the cut plane at 3'-6" in the style, does that work for each floor?
Can you attach more than one column to a grid location? I could do the layer thing, too, all columns in one element? Do you make the grid an element, insert it in a construct and then add columns? Isn't that the same as xrefing? Am I making this more complicated than I need to?
Thanks, Jill