lateral resistance in exterior wall 3

[jodster]

What is the best way to add lateral resistance to a 35 foot high exterior wall. The interior of the building is totally open so the walls are 35 feet high. I would like to install windows just below the roof trusses but do not wish to weaken the stucture. This building is 70 years old and was once an army drill hall. It is currently being used by gymnasts.

 

[dougantholz]

Not an easy solution. If you add thickness to the wall, and you are not is high seismic zone, then you will add shear capacity. Problem in a high seismic zone, you will be increasing the out-of-plane load on the wall - weakening the structure. If your building was originally used as an army drill hall then it may have extra capacity. If the owner is willing to do/pay for a very detailed analyisis of the wall you may be able to get it to work with opennings. Becareful, the local jurisdiction may still have this building in its emergancy response plans (especially if they haven't been updated in 20 years or so). If that is the case you will likely not be able to say the building works in a weaker condition since its importance factor will still have to be very high.

 

[boo1]

Have you consider a steel space frame insert to transer the loading and shear?

 

[CottageGuy]

Jodster,

Could the installation of the new windows not be done easily in conjunction with providing additional bracing of at the top the wall.

I do not recommend performing any work without the design of an engineer, but one idea might be to provide lateral bracing from the bottom of the windows to the roof diaphram. This would effectively "shorten" the wall. Keep in mind that you still have to transfer the gravity/uplift forces through to the wall.

Just one of many solutions.

CottageGuy

 

[rlflower]

Is wall thickness a limitation? Is astetics an issue? Perhaps you can "sister" vertical structural elements alongside the existing wall framing, thus supplementing the existing system. Pay attention to detail! The way that the connections are detailed must be done with care, especially since you are dealing with existing materials.

I would like to add to Cottage Guy's suggestion: since the problem we have here is out-of-plane loading, the only way to efectively shorten the design height of the wall is to provide substantial bracing (i. e., "kickers&quot from the roof framing. This might not look too bad if attention is paid to the astetic appeal of such a system enhancement.