Record-to-record variability in the seismic response of RC walls buildings subjected to ground motions matched to the conditional spectrum

In Performance-Based Earthquake Engineering, it is often necessary to be able to estimate the response of a structure whilst accounting for various sources of uncertainty. A number of simplified procedures have been proposed whereby record-to-record variability is accounted for using empirical estimates of dispersion. It is shown herein how the calibration of empirical dispersion estimates may prove challenging due to the numerous factors that influence dispersion. An alternative simplified numerical approach is examined, in which record-to-record variability is accounted for through use of the conditional spectrum. This simplified procedure is evaluated through a comparison with results obtained from nonlinear response-history analyses. Both inter-storey drift ratio and base shear are examined, with promising initial results.