FTAO wood shear wall -multiple openings question

Question

FTAO wood shear wall -multiple openings question

focuseng (Structural)

(OP)

10 May 16 16:32

Hi all. Anyone out there doing FTAO with multiple openings both horizontal and vertical? Imagine if you will a nice residential greatroom wall two levels high and several nicely spaced and symmetrical windows up and across. Any success or methodology out there to recommend? I feel like I have exhausted the available examples for insight of which there are only a few. I do not have "the Analysis of Irregular Shaped Structures" by Malone but have considered he might have done this. I have done multiple openings before horizontally but the vertical ones are not coming out right It is messing with the distribution of the vertical shear force I think. I would like to avoid FEA if I can but am somewhat resigned to this being an only option. I should mention I am using the Diekman method of analysis. It has occurred to me this is a bad idea anyway so if someone want to nail that down for me and rational thought I'd like to hear that too. Please don't offer alternate means of framing (such as moment frames, engineered panels, etc) as I just want to discuss the merits of this type of analysis and leave it at that.

Thanks.

______________
MAP

jayrod12 (Structural) · Answer 1 · 2016-05-10 21:15:37

Can you post an elevation of the wall?

If it's anything like the great room walls around here, there's no way I'd ever even attempt to consider it a shear wall.

focuseng (Structural) · Answer 2 · 2016-05-10 21:31:20

Sure thing. I figured V = 3400# (unfactored). If there were more windows then I wouldn't consider it, which is usually the case but it turned into an interesting exercise once I started chasing it. For purposes of discussion lets take the vault ceiling out of the equation. I have already dealt with the real world problem by another route so pressure is off but I really want to know if anyone has any thoughts for this as FTAO or if you have limits for this.

______________
MAP

http://files.engineering.com/getfile.aspx?folder=96ac750d-8b61-4066-8286-d2

KootK (Structural) · Answer 3 · 2016-05-10 22:14:31

Given the proportions, I would have probably just considered the central pier element on its own. Alternately, you might be able to work up something clever assuming the central pier element connected to posts either end by horizontal outriggers (below). I'd really have to be desperate or in the mood for some pro-bono before I'd head down that rabbit hole however. And sometimes I am those things.

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.

jdgengineer (Structural) · Answer 4 · 2016-05-10 23:51:47

I know not the answer your are looking for, but we do complicated FTAO walls in RISA. They have a really good module for wood shearwalls. If you have RISA I would look into that. It's really easy to complete the FTAO in RISA.

focuseng (Structural) · Answer 5 · 2016-05-11 20:50:51

Thanks jdgengineer. So with your experience with complicated walls what is your opinion of a configuration like this? Would you have looked at this and said "run the numbers". Do you have any examples just from a stress perspective of things? Does the RISA module check for pier ratios or does it utilize everything it can get a grip on? How is your confidence in the output?

______________
MAP

Come Join Us!

Posting Guidelines

FTAO wood shear wall -multiple openings question