2. Slenderness Effects and Sway or Nonsway Frame Designation
Columns and stories in structures are considered as non-sway frames if the increase in column end moments due to second-order effects does not exceed 5% of the first-order end moments, or the stability index for the story (Q) does not exceed 0.05. ACI 318-19 (6.6.4.3)
∑Pu is the total vertical load in the first story corresponding to the lateral loading case for which ∑Pu is greatest (without the wind loads, which would cause compression in some columns and tension in others and thus would cancel out). ACI 318-19 (6.6.4.4.1 and R6.6.4.3)
Vus is the factored horizontal story shear in the first story corresponding to the wind loads, and Δo is the first-order relative deflection between the top and bottom of the first story due to Vu. ACI 318-19 (6.6.4.4.1 and R6.6.4.3)
From Table 2, load combinations (2.3.2-4 No. 5 and 6) provide the greatest value of ∑Pu.
Thus, the frame at the first story level is considered sway.