CMU Pier - What do you do?

[Paul Andersen]

To date the bulk of my Revit projects have been concrete foundations with steel or concrete superstructures and thus my approach for masonry and wood projects is not fully tested and/or as polished.

I am currently working on a load bearing masonry structure with a precast plank floor system.
The walls are 12" cmu with built up 24" square cmu piers used to support tube steel framing that picks up the ends of the precast floor planks. My approach was to use a concrete column for the pier and change it's material type to "Masonry - Concrete Masonry Unit".

The problems I am having with this method are as follows:

The tube steel actually bears on a plate in the cmu pier. Since my approach for the pier was to use a structural column to get the correct analytical representation I am not able to show the tube penetrating the piers face in a 3D view. RS forces me to maintain an offset from the face of the column. Using a 2' wide cmu wall that is 2' long would allow me to toggle on the "Beam End Pocket Seat" but would not provide me with the correct analytical representation (plate vs stick).

My other issue is a little picky but I thought I'd throw it out there since the overall look bothers me. I'm currently using the same view range as found in the "Structural Analysis-default.rte" template. Associated Level for all: Top Offset: 2'-0", Cut Plane Offset: 1'-0", Bottom Offset: -4'-0", and Level Offset: -6'-0". My problem is with the 6th level which is where the CMU walls and piers stop and the roof structure begins. Since the cut plane is above the wall and cmu piers to accurately show the framing I lose the wall hatching and even though the cmu piers and walls are joined and show correctly when cut in plans below they have an annoying line between them when viewed in projection. I realize that the hatching is a cut plane hatch and is not showing because my walls are being viewed in projection with the current view range but is there a simple way to toggle this hatching on in projection views?

Thanks in advance for any suggestions.

[Tom Weir]

Hi Paul,
Happy New Year. I hope you had a good holiday.
<My approach was to use a concrete column for the pier and change it's material type to "Masonry - Concrete Masonry Unit".>
Up until Revit Structure was published for pure display it has been better to use an architectural column, which will fully integrate with the wall and its material type. And there is no snap to the center line so you can extend the beam member to its centerline.

But that ignores the analytical model doesn't it? Structural columns have never displayed well when integrated with walls. Might there be a way to add the architectural column with an added analytical line? Doesn't seem to be. I think structural pilasters need to be addressed by the developers and you are a stuck with it for now. We can't use the architectural columns anymore so we need a new improved one with analytical parameters added. That should be on our wish list.

The beam ends are also problematic. If you set the symbolic brace/beam cutback distance to 0" it will be applied universally to all column connections. Maybe that will work for you if you have not tube columns to worry about. We need each member to have a cutback distance parameter. Another wish list item. My low tech solution for you is to make a beam detail line style and fake it in where needed.

As for the masonry hatches not lining up go to a section view and use the align tool. That should help line up the hatches.
The walls do not seem to show projected hatches in plan as you state, and columns do, leading to a mis-match in display. Since they are projected though I would not want any hatch to show if I cut above the wall.

Well, the issue of structural columns and walls has been discussed many times on the Revit forum so these questions are not new to me. I believe we will see some improvements when RS3 comes out this spring with these probelms.

I tried to make my own model of your problems and basically got the same results. I definately feel your pain.

Have a great day....

Tom Weir
Los Angeles

[Paul Andersen]

Thanks for the reply Tom and happy new year to you as well. Took my first continuous week plus vacation in about 3 years so I'm feeling a little rusty today.

Thanks for the Align reminder, it doesn't seem to work in a 3D view which is where I was initially trying it, but the section view works pretty well to align the horizontal hatch lines (not much luck in keeping the vertical lines consistent but that is less noticeable anyways). I can also clean up the separation lines with the linework tool and invisible lines but aside from it being a lot of extra clicking it still has it's flaws. I get some ghosting issues at various angles of 3D viewing which may just be my video card - it displays a separation line as white instead of black.

Contrary to my previous post I agree that the hatch shouldn't show in projection but some consistent behaviour between the walls, columns and other families with regards to this matter would look better and save some time trying to clean up. I guess I'll have to dig for the material that is used for the tops of the walls and paint bucket the tops of the columns. I still don't understand why the join geometry won't clean up the separation lines in a projected plan view similar to how it does in a cut plan view - if you want it joined you want it joined regardless of the view right?

I did try the architectural column as well as creating some of my own families from scratch all with varying degrees of success. One of the biggest issues was as you mentioned that methods such as the architectural column which worked graphically for the most part didn't provide a way to incorporate the analytical linework/information.

Thanks for the low tech beam detail line solution for the plan work. I've resorted to this in the past but wanted to make sure I wasn't missing a better work around for this.

Thanks again,

[Tom Weir]

Hi Paul,
I guess my one question is to ask how important the 3D displays are in your work? Are you using them in your documents or presentations? I agree that it should all display better but hopefully it's not holding back your evolution to a modeling methodology.

Tom

[Paul Andersen]

To directly answer your question the 3D displays are becoming increasingly more important everyday. Prior to RS and other BIM software we were primarily using 3D CAD Software (Bentley MicroStation) and solid modeling software (formZ) to produce highly detailed models for presentation purposes on several of our larger more complex projects. While we leveraged some of the geometry from these models in our construction documents as isometric details and building sections they were primarily only developed and used for presentation and marketing purposes.

Now that RS is available and produces the bulk of the 3D images that we are interested in using as a by-product of developing the construction documents, we can reasonably use 3D images for presentation and construction documents on more projects than we have ever been able to before. The most important 3D views for us (bang for the buck and overall usability) with regards to construction documents are Hidden Line and Shaded with Edges. I realize that some of the issues I have with the way RS displays 3D views in these model graphics styles are picky, but they just stand out quite a bit to myself and our other users that have modeled in other software packages.

One primary example is the way that RS displays intersecting geometry in Hidden Line display. For example when a steel framing member penetrates the face of a wall in the case of a bearing pocket, RS does not produce the intersecting outline of the framing member at the face of the wall. This, in my opinion, looks unfinished and confuses the readability of the image. While I would like to see issues like these display better sooner rather than later I would still place them at a medium to low priority. These items are by no means slowing our use of RS but sometimes just makes us ask the question why? RS is just so good in so many facets of what it does that when we see issues like this it really stands out.

[Tom Weir]

Hi Paul,
We are finding ourselves using the 3D displays more and more, even though we do not have a history of using them like you do.

Tom

[tsbykatherine60220]

Paul and Tom,



I was playing around with these situations last night. I tried the approaches you mentioned Paul (24” sq mas column, 24” wide x 24” long wall) and found the same results as you, with regards to the analytical model, I placed a ¼” square pier centered in the 24” wide x 24” long wall and unchecked the analytical model box. I next tried using an additional 12” wide x 24” long wall alongside the 12” perimeter wall. This option gives no ghost lines but I still needed to add the ¼” square pier to get the analytical representation (I’m curious how this would get treated in the analytical software also??). I also unchecked the analytical model box on the 24” long wall; I’m not sure exactly how the analytical model should look in this situation though; with the 12” wide x 24” long wall it leaves a continuous line along the entire perimeter wall and I’m thinking that might not be desirable.



With regards to the top level, using the walls cleans it up nicely but using the columns forced me to add a white filled region (not too bad but on a complex building I’d rather not keep up with it). You mentioned something about applying a material to the top of the column, could you expand on that? It's not something I've seen yet.



About the situation where the line occurs when the pier and the wall meet; wouldn’t you want that line there as an expansion joint, typically we call for expansion joints where the wall changes width so what RS does with the columns works in that situation for us.



The display issue you mention in your last post is another one that I completely agree with. Is it a good method to create a solid void in the shape of a beam pocket and turn it’s visibility off? Check out the file I’m attaching and see what you think??



So much to learn!



Rick McElvain

[Paul Andersen]

Hey Rick, Thanks for your effort. The route you took with regards to the 1/4" square pier is interesting. I was thinking about how an architectural column family with a nested structural column might work for this situation but have not had time to test it. I think any work around for this is going to have a downside be it lack of analytical component, graphical display, scheduling, etc.

I've been trying to keep track of the analytical model as I create our construction documents. One thing I've noticed that I forgot to mention, and I see also happened in your example file, is that when you join geometry between a wall and a column for example the analytical component of the joined wall disappears completely.

Good solution for the beam pocket. I still think that intersecting geometry in general should show an intersecting line where the two meet instead of one disappearing into the other.

Point taken with the expansion joint. I guess I'm just thinking of monolithically poured concrete scenarios on other projects that would potentially have a similar problem.

With regards to adding a material to the top of the column you can simply use the paint tool (shortcut PT). Select a material from the drop down and hover near the edge of the top of a column. It appears for most wall types that the top of the wall utilizes the Shading color found in the materials dialog (for the case of the default "Masonry - Concrete Masonry Units" material RGB 227-227-227 Transparency: 0, Smoothness: 50 Shininess: 128 ). You could make a simple material with these settings and no surface or cut pattern and it should match nicely. A fancier solution that might work be to duplicate the family and add a separate material parameter for top of the column (haven't tested that yet). A couple clicks with the linework tool set to invisible line will clean up the separation lines between the wall and column. It does work . . . just seems like a lot of extra clicks.

Thanks again,