Question about bracing garage wall

[jimtheengineer10]

A client wants to have a 20' garage door and an 11' garage door on a 32' wall. This leaves 1'-8" on each side of the garage and 1'-8" in the middle. I have used the simpson strong tie wood strong wall portals before but the max opening is 16'-4". Anyone recommend any other options for providing the proper bracing for this scenario? Thank you.

 

[msquared48]

10'/3.5 = 2'-10" minimum SW length, so, one, three foot wall could work if the nailing is sufficient. You will just have to drag all the forces to it which the wall double top plate should be able to handle.

Mike McCann
MMC Engineering

 

[jimtheengineer10]

[ul]
[li]Does the 3.5:1 ratio apply at the building corners?[/li]
[/ul]

[ul]
[li]I just talked to the owner and he said an 18' door will work instead of a 20' door so I can get a 3' opening between the doors and 2' on each corner. Thanks.[/li]
[/ul]

 

[msquared48]

3.5:1 applies in any condition for plywood shear walls.

Mike McCann
MMC Engineering

 

[focuseng]

jim, are you trying to engineer the shear capacity of the wall or are you trying to prescriptively design the required wall bracing? It sounds like you have never engineered wood shear wall before.

the 16'-4" opening limitation is due to the "portal frame" method using the panels. If you use the panel straight up to the wall plate you do not have this restriction. Just watch your collector forces.

The 3.5 ratio is for "shear walls" not shear "panels". So you must engineer this out. The 3 side idea occured to me too but there may be L/W ratio limitations... don't know how it applies to you. All in the NDS.

Also a moment frame could work. Use the fabricated steel panel also but then is seems like the wall braces may be just as good for you.

If the concrete wall is raise to make the wood wall shorter wouldn't it be just cheaper to add a few more cu.ft. of concrete to the truck and go all the way? (I know... if you are working with carpenters this is just not reasonable.

______________
MAP

 

[dhoward26]

What about raising the stem wall to the point that you meet the height to width ratio? You could then potentially do a portal frame. At 18" you would need to raise the stem wall 4'-9". I know you will have some other special detailing but it might be an option. I have raised stem walls in the past, but not to that extent.

 

[AELLC]

If height of garage door = 7' then a 2'x7' shear panel meets the 3.5:1, and you use the portal frame method. I don't see any criteria or the garage door length.

 

[GlobeTrekker]

>
jimtheengineer10,

IMO, the simplest fix for your design, in your Seismic area, would be
the Simpson-Strongtie steel shear panel. The can be installed in
narrow wall sections down to 12" (max).

If you go this route, suggest you contact a Simpson-Strongtie rep. to
discuss your application. Also, when installing any engineered shear
panel, be sure to verify the manufacturer' min. width of any concrete
curb. Some are 4", others are 6" min.

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