The ASD combinations in IBC 2009 and IBC 2006 are based on ASCE 7-05, and are given in Section 1605.3, Load combinations using allowable stress design. Basic and Alternate sets of equations are given. The template file is RamSteelIBC2006_ASD.cmb. The Alternate combinations of 1605.3.2 are not implemented. The Basic load combinations used are those given in Section 1605.3.1:

D	(Formula 16-8)

D + L

(Formula 16-9)

D + Lr

(Formula 16-10)

D + 0.75L + 0.75Lr

(Formula 16-11)

D + W

(Formula 16-12)

D + 0.7E

(Formula 16-12)

D + 0.75L + 0.75Lr + 0.75W

(Formula 16-13)

D + 0.75L + 0.75Lr + 0.75(0.7E)

(Formula 16-13)

0.6D + W

(Formula 16-14)

0.6D + 0.7E

(Formula 16-15)

where E is defined as:

E = ρ QE ± 0.2 SDS D

(see ASCE 7-05 Sec. 12.4)

Q_E is the Seismic force from the analysis. ρ is the Reliability/Redundancy Coefficient as explained in the previously.

This definition of E results in the seismic combinations given in ASCE 7-05 Sec. 12.4.