Building sway in facades and claddings

[ryan_struct]

Our consultant is asking to consider 25 mm building sway in the calculation of facades attached to it. HOw would you simulate this sway in your FEM program(I use SAP2000)

 

[driftLimiter]

Is the model for the building or for the facade?

 

[milkshakelake]

For me, this comes down to limiting the deflection of the facade. If the building swayed 25 mm, you check that against a facade deflection of whatever the limit is, like L/400. I'm not sure how an FEM model would come into play unless it was a curtain wall or other engineered system.

Usually, it's the other way around. The FEM model "produces" the sway, and the facade deflection is checked if it's exceeding this or not. 25 mm is a very low amount of sway, especially when considering things like deflection amplification with seismic loading. They might be asking you to limit the whole building deflection to that much, which is a difficult task.

 

[MotorCity]

Design the connections between the cladding and the building to tolerate the movement. I am guessing the 25 mm is the lateral drift of the building at the top. Figure out what the differential drift is across the cladding unit and design for that (not the total building drift).

 

[XR250]

What happens at the corners of the cladding? How the sway resolved there?
That was always my issue with these newfangled cladding clips that allowed for horizontal movement. The arch. would spec them but never deal with the corners.