Wind Load Conversion Factor???
Wind Load Conversion Factor???
(OP)
I am dealing with a much higher wind loading than normal for one project and want to make sure I get things right here...
I am used to dealing with ASD loads for wind under ASCE7-05 and IBC 2006. In looking at IBC 2012 and ASCE 7-10, the loads are much higher. I know this has been addressed before in the forums, but the search function is not working for me.
My questions are:
1. Are the 7-10 compared to the 7-05 loads merely about 1.4 times greater, intended for direct application to LRFD equations?
2. Can I merely divide these 7-10 values by 1.4 to get the ASD loads, using the appropriate load equations and material tables?
I am used to dealing with ASD loads for wind under ASCE7-05 and IBC 2006. In looking at IBC 2012 and ASCE 7-10, the loads are much higher. I know this has been addressed before in the forums, but the search function is not working for me.
My questions are:
1. Are the 7-10 compared to the 7-05 loads merely about 1.4 times greater, intended for direct application to LRFD equations?
2. Can I merely divide these 7-10 values by 1.4 to get the ASD loads, using the appropriate load equations and material tables?
Mike McCann, PE, SE (WA)






RE: Wind Load Conversion Factor???
But at the end of the day, my understanding is that a 7-10 wind load with a 0.6 factor for ASD load combinations should produce about the same result as the old 7-05 wind loads for ASD. (Or a difference of 1.6~=1/0.6)
RE: Wind Load Conversion Factor???
RE: Wind Load Conversion Factor???
1. 7-05: 90 mph wind yields 1.0 Wind (ASD) is equal to 7-10: 115 mph wind yields 0.6 Wind (ASD)
2. Multiply 7-10 values by 0.6 or whatever your ASD combination requires.
RE: Wind Load Conversion Factor???
However, I think the wind speed maps may have changed in a (very) few areas. So you may want to compare the 2 codes if it is pertinent to your project.
RE: Wind Load Conversion Factor???
RE: Wind Load Conversion Factor???
RE: Wind Load Conversion Factor???
2. mult by 0.6 not 0.7
The numbers for most conditions as essentially the same. The small differences are due to rounding the contours to multiples of 5mph
RE: Wind Load Conversion Factor???
http://windspeed.atcouncil.org/
RE: Wind Load Conversion Factor???