Residential Garage Shear Wall Combined With a Steel Moment Frame 1

[jakordas]

When designing a residential garage there is usually an issue with the front wall (the one with the garage doors) being able to resist the lateral wind loading. Depending on the situation this is taken care of with either a wooden shear wall design or steel moment frame design. I would like to know if anyone combines the effect of both? Basically if a wood shear wall has an aspect ratio that is to small to be a shear wall or if the wall is just not strong enough to be a shear wall, is there anyway you can combine its effects with a steel moment frame to allow for a reduction in steel?

 

[jeffhed]

If the aspect ratio of a wood wall is greater than 3.5:1, you cannot use it. I would be very surprised it a tall skinny wood shear wall would give you any legitimate reduction in steel. I've never compared it before, but I would think the stiffness of the moment frame would be significantly higher than a single skinny shear wall. If you are using a steel moment frame just use it to do the job. I usually don't need to use a moment frame on residential garages. Many times you can use the APA portal frame in the IBC or strong walls or hardy frames if your parameters are such that you can't use the portal frame.

 

[jakordas]

Thank you for your post.

 

[msquared48]

Or you can raise the height of the concrete stem wall to lower the aspect ratio to the level that works, or just pour a concrete shear wall. Seeing a lot more of that done here recently.

Mike McCann, PE, SE (WA)

 

[jakordas]

I like that idea very much. Thank you.

 

[XR250]

You may also want to look into designing it as a three side building

 

[msquared48]

Personally, though, I would not want to ride a three legged horse.

Mike McCann, PE, SE (WA)

 

[TehMightyEngineer]

Depending on the garage it can be done as a three-sided structure. I did my father's garage as a three sided structure, hasn't fallen down yet.

Professional and Structural Engineer (ME, NH)
American Concrete Industries

http://www.americanconcrete.com

 

[XR250]

Beats a two legged horse

 

[jeffhed]

Depending on your loads and if your height to width ratios work, you could run the header continuous over the walls and tie it down or run coil strap and blocking through the length of the walls and tie it to the header. This could shorten your walls to the height of the opening and then design the walls as a force transfer wall. Sometimes works, sometimes it doesn't.

 

[EngineeringEric]

Why not use portal frames? depending on height of wall a pretty small panel works and now it gives 1.5xLength for contributing length
CS-PF, PFG, PFH

 

[jakordas]

Thanks everyone I will definitely keep the portal frame in mind for the future. I ended up going with a simspon strong wall. This required them to adjust the garage door spacing but it worked in the end.