Torsional Wind Load Cses 1

[nataliab]

Could anyone explain to me Figure 27.4-8 in ASCE-10, showing torsional loading cases (2&4)?
Should I put to the structure uniformly distributed load + MT, or only MT?
That scheme is quite confusing to me.
Thanks for any advice

 

[wannabeSE]

natalib,

Per the notes in figure 27.4-8, the reduced uniform load plus the torsional moment is used.

"Case 2. Three quarters of the design wind pressure acting on the projected area perpendicular to each
principal axis of the structure in conjunction with a torsional moment as shown, considered
separately for each principal axis."

 

[nataliab]

Thank you for the reply,

I' m just wondering, how will structure react for superimposing that load case.
In basic load case (before multiplying by 0.75) I have 206,3 lb/ft (for highest story). To obtain torsion, I applied trapezoidal load pattern (semirigid diaphragm)with values 15.5 and 294 lb/ft on the edges. By applying 0.75*206.3 lb/ft and trapezoidal load pattern simultaneously I will get on one edge of diaphragm 2x grater load value than in basic load case.
Is that correct?
I am new to ASCE 7, so I would appreciate your help in understanding of that issue.