New Seismic Vulnerability Index for Vertically Irregular Buildings

Most international design codes either prohibit construction or recommend alternative seismic analysis and design of vertically irregular building frames, depending on the degree of irregularity and site hazard. However, the irregularity quantifiers recommended by design codes and published literature do not appear to correlate well with the potential for seismic damage. A new parameter, the seismic vulnerability indicator (SVI), is proposed based on the interstory drift ratio damage parameter to indicate the expected seismic risk of any building with single or coupled vertical irregularity. The SVI is computationally simple and found to correlate well with the potential seismic risk of all categories of vertically irregular buildings. (C) 2018 American Society of Civil Engineers.