All axial compression members are calculated as long bars, i.e., with allowance for slenderness (λ = l₀/i_min ). The calculation is performed in accordance with the clause 5.3 of SNiP 2.01.07.- 81*, buckling coefficient φ is determined by formula 8-10. Effective bar lengths (within and out of plane) taking in to account role and location of the bar in the structure, as well as fixation of ends (l₀ = μl), are determined according to requirements of chapter 6 or addition 6 to SNiP 2.01.07.- 81* and are set by specification of members. Slenderness of compression members (CMN) shall not exceed limit values given in table 19 of SNiP 2.01.07.- 81*. Value of coefficient α being used in table 19 is taken within limits from 0,5 to 1,0. Limit slenderness value depends on stress acting in the member, section area, buckling coefficient and design resistance of steel.