Seismic response of buildings during earthquakes : Experimental results from strong motion data

The kinematic behaviour of 25 "standard" buildings is derivet from an analysis of 29 accelerometric record sets obstained by the California Strong Motion Instrumentation Program during recent earthquakes. Measurements of the main natural frequencies, modal shapes, and corresponding dampings, are abstained by means of a multi-sensor, multi-degreeof freedom linear system identification technique, while various spectraltechniques (Fourier spectral rations, coherence analysis) provide reliable, quantitative estimates of the amount of torsional and rocking motions (where there is adequate instrumentations) (AU)