NEHRP Clearinghouse

Statistical Evaluation of Nonlinear Response of Seismic Isolation Systems. Volume 1.
Kircher, C. A.; Lashkari, B.
National Science Foundation, Washington, DC. Directorate for Engineering., June 30, 1989, 285 p.
Identifying Number(s)
The study calculated the seismic response of 31 different isolated buildings using nonlinear time history analysis. The buildings were modeled as rigid structures supported by bilinear, hysteretic isolators whose properties were varied from model to model to produce effective periods of 1.0 to 4.0 second and effective damping values of 5% to 40% of critical. Each isolated building was analyzed using a set of earthquake time histories that represent the Seismic Zone 4 ground motion criteria of current building codes for a structure located at either a rock, stiff soil, or medium soil site. The study has compared calculated responses with the design requirements proposed by the Structural Engineers Association of California (SEAOC) for design of isolated buildings. The results of these comparisons provide a basis for judging the validity and applicability of the SEAOC design requirements, and for modifying the requirements, as appropriate.
Dynamic response; Damping; Building codes; Earthquake engineering; Earthquake resistant structures; Loads (Forces); Hysteresis; Structural design; Mechanical properties; Structural engineering; Tables (Data); Dynamic structural analysis