ASCE 7-02 Gust Effect Factor

[sme75]

What is the highest value you have calculated and used for the gust effect factor, Gf? I am working on some tall vessels, which require me to use section 6.5.8.2 to calculate the factor. They are fixed at the base and have a guide to brace the vessel laterally at approximately half way up the vessel. I can see that the damping ratio can affect the calculation significantly and I have been tyring to be conservative, but I don't want to go overboard. Is a value of Gf = 1.4 unreasonable or have others used similar values for design?

 

[SacreBleu]

I would use 1.4 only for small structures (small signs, etc). For a large vessel, I would use somewhat less than 1.4, but I am not 100% clear on the interpretation of ASCE 7-02.

 

[warrenw]

sme75:
I just looked up some recent projects and one was a 195' self-supported stack and the Gf used on that was 1.35.
Your value of 1.4 does not seem unreasonable.