Out-of-Plane Masonry Wall Design Loading

[Brad_S]

I have a simple rectangle commercial building with masonry sheer walls. We are looking to design the out of plane loads on the walls. The building is 144'x57' and the wind and seismic out-of-plane loads need to be considered. For the wind case, I have the wind loads acting in plane and have distributed them to the side walls that are out of plane. I have also generated the side wind forces acting on the walls. If I want to design a 1' strip of the out of plane wall is there a way to go about that?

All the codes and information do not seem to mention anything reffering to how to handle biaxial loading that will be caused by the forces acting on the out of plane wall.

I am still very new to this field and apologize if this question is worded weird or very simple. I have been struggling and reading codes for almost a day attempting to figure this out.

Thank you,
Brad

 

[jayrod12]

I don't know of anyone that designs a wall for both in-plane and out-of-plane simultaneously. If you have maximum design level loading in one direction, you can't have maximum design loading in the other acting concurrently.

 

[BridgeSmith]

For sign structures, the AASHTO sign spec. combines orthogonal wind loads at 100% for the primary and 20% of the load in the secondary.

 

[DaveAtkins]

For out of plane wind loads, the walls should be designed for Components & Cladding loads, since this will be worse than MWFRS loads.

DaveAtkins

 

[KootK]

There are a handful of situations where I'll look at in and out of plane lateral together.

One of them is a stair shaft at the perimeter of a building where I may be claiming that the walls span horizontally. Then, I'll add my shear wall rebar demand to my out of plane lateral load rebar demand. Fortunately, your shear wall boundary elements are usually pretty close to return walls and are therefore unlikely to be affected by out of plane.

Another case, more relevant to your project, is squat shear walls where the vertical reinforcement is a calculated necessity. There, I may add the rebar demand from in and out of plane flexure. One time I looked at the effect of combined action on the compression stresses in one of these walls but that seemed to be very far from critical so I haven't bothered since.

You can get pretty high cross wind to match the wind causing in plane wall shear. It kind of becomes a load casing nightmare though.

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.

 

[structSU10]

If it happens to be an exterior wall you get side wall pressure for MWFRS analysis concurrent with in plane shear. It likely won't mean much though.

 

[WARose]

All the codes and information do not seem to mention anything reffering to how to handle biaxial loading that will be caused by the forces acting on the out of plane wall.

For masonry.....it's pretty straight forward. You just combine the stresses (algebraically) and compare them to the allowables.