ASCE 7-98 Torsional moment

[tntn]

I am designing a pre-engineered building as per ASCE 7-98. As far as wind load is concerned, I don't know how to apply torsional moment as mentioned in figure 6-9 (section 6.5.12.3) to the 2-D rigid frames. Would you please explain to me the nature of this moment and how to deal with it ?
Thanks.
Duong, Sai Gon, Viet Nam

 

[Lion06]

You would get the torsional moment for the building, not the frame. That torsional moment for the building will change the lateral force going into each frame.