Overall Safety Assessment of Multistory Steel Buildings Subjected to Earthquake Loads. Evaluation of Seismic Safety of Buildings

摘要

A set of 140 earthquake records was used to assess the uncertainties involved in ground motion representation. In particular, seismic input was characterized in terms of the Kanai-Tajimi power spectral density function and the strong-motion duration. Based on the method of spectral moments, key Kanai-Tajimi parameters were determined for the set of records. The statistics and interdependencies of these parameters were evaluated. The correlation between these K-T parameters, strong-motion duration, peak ground acceleration, epicentral distance and local magnitude was investigated. Based on an extensive simulation study, semi-empirical modifications were made to an existing random vibration solution for single-degree-of-freedom elasto-plastic systems. Similar modifications were incorporated in an approximate multi-degree-of-freedom elasto-plastic random vibration methodology for shear-beam systems, and its validity was assessed by a series of compatibility studies. By using the random vibration methodology, the overall inelastic seismic safety analysis of buildings was formulated. Also, for a hypothetical Boston site, the degree of overall seismic safety was assessed quantitatively for several multistory steel buildings designed by different procedures.