Design philosophy (Seismic: AISC 341)
All members are designed as per the normal AISC Specification rules for the seismic load combinations.
Additional design rules are required for seismic combinations. These are as per the AISC Seismic Provisions (Ref. 5). These rules are applied as follows:
- If SDC = A - no additional requirements
- If SDC = D, E or F, apply rules for AISC 341
For each of Direction 1 and Direction 2:
- If SDC = B or C and R ≤ 3 - no additional requirements
- If SDC = B or C and R > 3, apply rules for AISC 341
Where requirements are necessary then they apply only to the members of the SFRS and are only checked for the seismic combinations.