NEHRP Clearinghouse

Title
Overall Safety Assessment of Multistory Steel Buildings Subjected to Earthquake Loads. Evaluation of Seismic Safety of Buildings.
File
PB81111718.pdf
Author(s)
Lai, S. S. P.
Source
National Science Foundation, Washington, DC. Engineering and Applied Science., June 1980, 285 p.
Identifying Number(s)
R80-26
Abstract
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.
Keywords
Seismic design; Earthquake resistant structures; Probability density functions; Buildings; Earthquake engineering; Random vibration; Power spectra; Dynamic structural analysis