Application of ASCE 41 to a two-story CFS building
The objective of this paper is to summarize the evaluation results from applying the updated performance-based seismic design provisions: ASCE 41-17, on a cold-formed steel framed building sited in a location with high seismic demands. The assessment included examination of the existing design and consideration of retrofits required to bring the design into compliance with ASCE 41-17. The assessment of the building relies on the linear procedures and m-factors in ASCE 41-17 and follows the same basic process as the original design. Despite the fact that the studied building is compliant with ASCE 7 and AISI S400, and successfully withstood shake table testing in excess of maximum considered earthquake levels with no permanent damage and no residual drift, ASCE 41-17 finds the building to be deficient. The work highlights that, for cold formed steel framing, even though ASCE 41 is based on the same tested shear walls that ASCE 7/AISI S400 rely upon, the component-based procedures of ASCE 41 do not easily account for the larger system overstrength and ductility that are included and validated for actual systems. Further work is needed to improve ASCE 41 to account for full system performance, this is particularly important given ASCE 41’s growing role as the benchmark performance-based standard for seismic assessment and design.