Horizontal bracing not in horizontal plane

[ranga.narasimhan]

Hello all,

Please look at the picture below. I am trying to put a simple horizontal bracing (using Revit bracing tool).

- On lower left corner, I have two identical 'W' beams intersecting at a vertical column.

- On the other end of bracing I have a main 'W' beam and joist 'channel' intersecting.

- The joist 'channel' and 'W' beam are different heights (10" & 12").

The problem is that, the bracing I put is not perfectly in horizontal plane. It is because the bracing is always drawn from centre of beam and centre of joist. How to have the bracing in horizontal plane?

Thanks

Ranga

[erik_snell]

The Bracing placement tool is for Vertical and Kicker Bracing. When you select one of the elements created with this tool the Structural Usage property will show these options. For Horizontal Bracing, use the standard Beam placement tool and set the Structural Usage property to Horizontal Bracing. 

[ranga.narasimhan]

Thanks Eric,

1) I already tried that too. If I use standard beam , the horizontal bracings are placed such that they are inline with the top flange of the beams & joists. The usual place to connect bracings is in the webs of beams.

How to solve that issue? Use Z offsets?

2) Also, when I use standard beams, If I drag the beams/joists, the bracings dont update their positions. They kind of become disconnected from parents beams.

What about that?

Please see the attached small screen recording for better understanding of the problem.

Thanks

Ranga

[erik_snell]

The beam and brace do have different joining mechanisms driving the behavior. I'm not sure why the join is failing so consistently. You may want to use snap references from different elements. For example, try to snap to the end of the channel instead of the intersection.

In these cases, I think you will get the better change behavior using the braces. To get the geometry positioned better vertically you would need to use a little math and adjust the z Justification. To control this a bit better across many braces, I would suggest using Global Parameters to drive the justification.

Unfortunately, in coarse level of detail the brace symbology are different from the beams.

[ranga.narasimhan]

Hi Eric,

I did try that too.

1. I always pick end points rather than intersections. That way Revit knows where to locate bracing exactly. Still the behavior is same, they don't work properly.
2. I also tried Z justifications (for bracings made with beams tool). Still I have same issue.

I can not figure what is the issue.

The other thing is that, when I draw with 'bracings tool', on the properties window-> structural usage, there is no "horizontal bracings". Only vertical bracings, kicker bracings are available.

But when I draw bracings (made with beams tool), I have "horizontal bracings" as an option in structural usage.

That sounded weird to me. Does Revit not want to horizontal bracings with 'bracings tool'?

Thanks
Ranga

[ranga.narasimhan]

Also,

Look at the beam cut back issue, when using a bracing tool vs beam tool.

Regards

Ranga

[erik_snell · Accepted solution]

The bracing tool and its behavior are specifically designed for vertical bracing. The beam tool and its behaviors do align better with beams than bracing. Horizontal bracing would most likely warrant behaviors that fall between bracing and beams. My next suggestion would be to have you go and enter a new idea at the Revit Ideas forum, as the behaviors you are asking for would require additional features added to the product.

Cheers!

[ranga.narasimhan]

OK Eric. Thanks.

I'm wondering why it is not there in Revit all these years. Horizontal bracings are a fundamental structural design element. And how do structural engineers deal with this elementary issue all these days? I have no clue.

Anyways, thanks again for your responses.

Regards

Ranga