Pre-Fabricated Gable Frame Design in High Snow Regions- Comparison of LRFD and ASD

Naser Katanbafnezhad, Alan Hoback

American Journal of Engineering Research (AJER), vol. 9(6), 2020, pp. 160-168.


The LRFD and ASD methods do not produce the same designs. The biggest discrepancies are in cold regions with a high snow load because of different ways of handling the safety factors for snow. The results were shown for structures in Berlin, NH and Government Camp, OR, USA which are located in high snow regions. Precise practical designs of gable frames with a high snow load show that LRFD and ASD can produce results that vary by up to 41% with LRFD usually producing the lighter weight design for roof angles above a pitch of 7 to 12. Results were a function of other loads, roof angles, and span to height ratios. The implication is that designers in cold regions need to either be familiar with how the methods vary, or design with both methods in order to find the least weight design.

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