The requirement to perform a second-order analysis is satisfied by performing a first-order analysis and calculating and applying B₁ and B₂ factors to the design forces as outlined in Section C2.1b of the Specification. Those factors need to be calculated for each load combination. They are applied to the member forces as indicated in the following equations:

Mr = B1Mnt + B2Mlt

Eq. (C2-1a)

Pr = Pnt + B2Plt

Eq. (C2-1b)

where

Mnt	=	the non-translational Moments
Mlt	=	the lateral translational Moments
Pnt	=	the non-translational axial forces
Plt	=	the lateral translational axial forces

B₁ and B₂ are defined below

The program assumes that M_nt and P_nt are the moments and axial loads due to the vertical gravity load cases and that M_lt and P_lt are the moments and axial loads due to the lateral load cases.