This question was asked a few years ago but not answered.
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 - “Load Resistance Factored Design”)
or
0.6 (for ASD - “Allowable Stress Design”).
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)?
Is the reaction a service load reaction or an ultimate reaction?
If AutoPipe doesn't reduce the wind speed internally then I'd think they're over-calculating the stress on the pipe produced by the wind (unless they're factoring up the thermal, gravity, pressure, etc forces as well).
Another way of asking the same.
Are the ASCE 7-10 wind loads/reactions reported by Autopipe factored by 1 for LRFD design or 0.6 for ASD design?
In the calculation of allowable occasional stress are the wind loads factored by 0.6?
Hello Kevink,
The wind results (pipe forces and support reactions) are based on the methodology provided by ASCE 7 Standard. Most of the ASME Piping codes design is based on ASD. AutoPIPE only has DNV 2012 piping code in which the design is based on LRFD.
Regards,
Mike DattilioBentley Systems Design AnalystDesign Engineering Analysis group===================================================
Thanks Mike
We have worked out of some this.
If the wind pressure is used for the wind load then the results for restraint loads is pipe area * pressure with no factor.
Can you please confirm that code check, Sus + W, uses the forces, as above, with no factors?
Thanks
Kevin