Stud wall bracing 2

[oengineer]

I have a question regarding stud wall bracing.

I have 12’ high metal stud walls for a building renovation for an indoor Volleyball court. There is no ceiling, the stud walls are partitions and open above to the 24’ plus roof height. Stud walls usually have diagonal bracing at the top to keep them supported laterally and this is usually concealed by a drop ceiling.

The client doesn’t want to see diagonal bracing all over the place going up to 24’ or 30’ high in some places. This would not look good.

Would anyone happen to have any suggestions on how I can specify the walls to have internal x’bracing or something to make them structurally sound from falling over without using diagonal braced studs from the top track of the partitions all the way up to the roof deck?

Any comments/suggestion are appreciated.

 

[oengineer]

@Jayrod - Thank you for your response.

Another design option that I have is this:
1.) Use cantilever double angle back to back columns @ 8’-6” o.c. with infilled studs @ 16”o.c. (See Sketch 1). This would be just for the 12’ height. The track (or box header) is like a girt and is composed of double angles front to front. The columns would have 12x12x3/4 base plates with (4) - ¾” dia. HIT-HY 200 + HAS-E ½ Hilti Bolts. The effective embedment of the Hilti Bolts into the slab would need to be a minimum of 3.5 inches. (see attachment) This partition is designed for a 5 psf horizontal load based on IBC 2006 Sec 1607.13.

http://files.engineering.com/getfil...6-987a44caad79&file=Wall_Option_-_Sketch_.pdf

2.) Extend some of the studs all the way up to the bottom of the deck and provide girts ( as previously mentioned in this post).

@KootK - The client doesn't seem to be concerned with the aesthetics regarding the use of a ceiling for these walls. At this point my main concern is that it will structurally function.

 

[jayrod12]

If you're confident in your solution number 1 calculations, that would probably please the architect the most. I do however have my own reservations that double angles at that height and spacing will provide a comfortable wall. Will it be strong enough to not fall over? Likely. Will the wall have some significant give when someone leans against it? also likely. I think the double angles may be better off being channel sections, or light W sections to stiffen them up considerably.

 

[oengineer]

@Jayrod - I'm sorry I wrote the wrong thing. I designed it with double channels, double c6×10.5 back to back.The box header is also composed of double channels.Im only using channels.

 

[jayrod12]

Without running a number, that's more in line with what I would expect. I'd still keep a close eye on deflection of the box header at mid-span between the posts, taking into account the deflection of the posts as well.

 

[oengineer]

@jayrod12 - Thank you for your input.

@Everyone - Thank you all for your help.

 

[KootK]

In my market, I would get serious push back on anything that involved anything more serious than cold formed framing in something like this. Hot rolled steel would raise eyebrows and, certainly, the base plate projecting beyond the wall plenum would be a problem. For these reasons, I'd be inclined to save myself some effort and skip right to an all cold form solution if at all possible. Cold formed horizontal bracing at the ceiling as required.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oengineer]

@KootK - There is no ceiling for the 12 stud wall. The bottom of deck is 12 ft taller than the stud wall.

 

[KootK]

I understand oengineer. I thought that you had the option of placing bracing members in the plane of what would be the ceiling if you had one. That's how I interpreted these comments:

The yellow highlighted portions are the wall and the pink highlighted portions are horizontal braces to be used.

@KootK - The client doesn't seem to be concerned with the aesthetics regarding the use of a ceiling for these walls.

This is, in fact, the approach that I typically see. I do some glass work and much of it is interior office partitions in situations just like this.

Would it be possible to have the 10 ft to 12 ft high stud wall just brace to the existing metal building and it self?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oengineer]

@KootK - The use of this building is for an indoor volleyball arena.

 

[KootK]

I'm afraid that you've lost me. The plan that you posted showed offices. Are you expecting fast moving sporting equipment to be flying around this space? If so, you probably want block walls or a veneer/cfm alternate.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[KootK]

And I suppose that my question for you is simply this: can you or can you not have horizontal framing members at the would-be ceiling level? If you can, then I stand by my previous comment. If you can't, then I retract my recommendation.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oengineer]

@KootK - Well my concern, based on other responses in this form, is the overturning of the the wall due to a lack of a top lateral support with adequate load transfer to the main structure. This is why I designed the moment connection base plate, based on previous recommendations in this post.

Are you saying you would not be concerned about the possible overturning of the wall?

 

[KootK]

Are you saying you would not be concerned about the possible overturning of the wall?

Sure I'd be concerned about it. I'd evaluate it and deal with it by supplying some form of bracing to the wall tops with cold formed members. That is, of course, if such cold formed bracing members could be installed at the tops of the walls. You still haven't let me know if that's the case.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oengineer]

@KootK - you can have horizontal framing members at the would-be ceiling level. Based on several of the comments in this post, the question is what should be done to resist the overturning since the wall are no longer have lateral support a the top with adequate load transfer to the main structure. How would keep the wall from twisting?

 

[oengineer]

@KootK- What type of form of bracing to the wall tops with cold formed members would supply for the situation?

 

[KootK]

- split diamond
- add bays as needed to make the top track spanning member work.
- hang the bracing from the structure above as needed.
- drag lateral load back back to parallel shear walls or base building.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oengineer]

@KootK - I see what you are doing. Interesting. But to some degree you are making a type of ceiling over the rooms. Interesting concept though.

 

[oengineer]

@Kootk - And by doing this, you are allowing the studs in the walls to act as supply supported instead of cantilever.

 

[KootK]

But to some degree you are making a type of ceiling over the rooms.

Well, yeah, that’s why I keep asking if it was acceptable to put bracing in the would be ceiling plane.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[oengineer]

@KootK - Thank you for the suggestion!

I thought you were going to brace it like I show in that sketch.

I will investigate your idea.