Snow Load on Moment Frames
Snow Load on Moment Frames
(OP)
I am in SDC D designing a steel moment frame for a two-story 20-foot tall moment frame. My roof snow load is on the order of 150 psf. Can I use an ordinary moment frame? the code says I can if my dead load is less than 35 psf. It doesn't say seismic mass, which would include the snow load. I appreciate your feed back and comments!





RE: Snow Load on Moment Frames
RE: Snow Load on Moment Frames
I should elaborate: It seems to me that the ASCE 7-05 is not allowing ordinary moment frames in SDC D when the frame is bracing heavy structures (12.2.5.7). Wood framed buildings are not heavy. However given the amount of snow here we design with 20% of snow load as part of the seismic weight (12.7.2).
In response to your first comment: I'd agree with the code regarding the percentage of snow that is added to the seismic weight. Last winter I had three feet of incredibly dense and hard packed snow over (and completely bonded to) about a foot of ice which was completely interlocked with my asphalt shingles, all locked into a maze of valleys and prevented from sliding by an ice dam at the eave.