Top and Intermediate Wind Girder Calculation - Sect 5.9.6 and 5.9.7 1

[rab1944]

Can someone provide the reason for the change in the Z formula from (V/100)^2 to (V/120)^2 in the last part of the formula?
The same question applies to the H1 formula where it changed from (100/V)^2 to (120/V)^2.

I know this is old news but your comments would be appreciated.

 

[JoeTank]

API adopted the same wind speed criteria as ASCE-7. The newer codes use the max 3-second gust speeed rather than the sustained wind speed. The old 100 mph design load is equivalent to a 120 mph max 3-second gust. The design requirements of API have not changed, only the form of the equation.

Joe Tank