Freezer Building Deflection Limits
Freezer Building Deflection Limits
(OP)
Does anyone have suggestions on what to limit deflections to for a stand alone freezer building? Roof members, wall panels and frame sidesway?
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Freezer Building Deflection Limits
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RE: Freezer Building Deflection Limits
Analysis and Design of arbitrary cross sections
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RE: Freezer Building Deflection Limits
RE: Freezer Building Deflection Limits
The first thing I’d do is contact a couple suppliers of the insulated panels which might be used on the job. Ask them what their limits are, and what their connection details look like, and how they work. Generally speaking they can accommodate fairly typical bending and deflection perpendicular to the plane of their panels. That is to say, roof loads and wind loads and their deflections are not usually a problem. The problem is with the bracing of the building, and the need for a very low drift type deflection (racking) as the building tries to take lateral loads. The insulated panels are very stiff in their own plane, and they will try to take lateral loads as if they were a shear wall. But, since they are 4 or 6' wide and 18' tall, and then joined edge to edge with air tight seals, they tend to rock (rack independently) on one lower corner (wind direction dependent) when laterally loaded, in plane. This quickly destroys the sealed joints. I’ve seen ice cycles 16' high, 3' wide and 2' thick hanging off the outside of the building at these failed joints. At the outset the insulated panels are stiffer than a poorly braced steel frame building, and will try to take the lateral loads. This really over works the panel joint seals very quickly. The upshot is that you really have to x-brace the exterior walls, and adjust that bracing (tighten it up) prior to final commissioning. This will limit the amount of lateral deflection the panels must deal with. Don’t forget the underfloor insulation, insulation at column bases, and underfloor venting/warming system.