I am very impressed to your web section to let STAAD generate wind load for truss tower. It will save us a lots design time to do it. We design and analyze open structures and towers daily. Per our understanding and interpolation for ASCE 7, the calculated wind load F=qz G Cf Af are only applied to members on the front face of tower, not all members of tower. If apply wind load on all members as you demonstrated, the result force are doubled. Could you think which interpolation of ASCE 7 is correct? I have another question that how to apply the wind load to a few special members, not all members? It is hard to do it with X, Y, Z ranges.
KC Fong
kc.fong@jacobs.com
Jacobs Engineering
When the open structure option is chosen in STAAD.Pro, it would apply the wind load on the face of all members and not just on the members at the front face of the tower. However you can always control which members to load. Please refer to the post below which explains how to do this
http://communities.bentley.com/products/structural/structural_analysis___design/f/5932/p/116624/358442#358442