Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Subarea: Original Author: Bentley Technical Support Group Problem: Up 'til now, we had been using ASCE 7-02 (7-05) and getting service wind load reactions from our mechanical guys. We've started to switch to ASCE 7-10, as was inevitable, and I put it to them whether we were getting Service or Ultimate loads. They did not know and couldn't seem to find out the answer. Rather than conduct an experiment, comparing output for the two different codes at the respective equivalent windspeeds, I thought we should just ask you guys for documentation. I had given them the ASCE 7-10 ultimate wind speed (say 115 mph instead of the 90 mph which was typical for most of the continental US, OC I & II bldgs) and told them to set their code to ASCE 7-10, but wasn't sure if I should factor the reactions they were giving me by 1.0 (for LRFD) or 0.6 (for ASD). So does AutoPipe give us Service Loads (for consistency between 7-02 and 7-10, as neither really means anything to mechanicals) or does it give us the Strength Level Loads (because we give it the ASCE 7-10 wind speed and set the code to ASCE 7-10)? Answer: Short answer, use the higher speeds when using ASCE 7-10, e.g. ultimate wind. This comes from the help for ASCE 7-10 wind loads: Basic wind speed at 33ft (10m) ASCE 7-10 defines this as the nominal design 3-second gust wind speed at 33 ft (10 m) above ground for Exposure C category. This depends on the geographical location. ASCE 7-10 provides maps for wind speeds in the USA. The basic wind speed varies from 85 miles/hr in the US West Coast states (California, Oregon and Washington) to 170 miles/hr in Guam. The wind speed can be determined from Figure 26.5 provided in the ASCE 7 code . Note: 1 mph =1.60934 km/hr and 85 mph = 136.8 km/hr = 38.0 m/s Find further details on the calculations under "Reference Information - Analysis Considerations - Wind Analysis - ASCE-7-10 Wind Loading Calculations" See Also Bentley AutoPIPE External Links Bentley Technical Support KnowledgeBase Bentley LEARN Server Comments or Corrections? Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to the "Comments" area below. THANK YOU!
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