Use of the conditional spectrum to incorporate record-to-record variability in simplified seismic assessment of RC wall buildings

A procedure for incorporating record-to-record variability into the simplified seismic assessment of RC wall buildings is presented. The procedure relies on the use of the conditional spectrum to randomly sample spectral ordinates at relevant periods of vibration. For inelastic response, displacement reduction factors are then used to relate inelastic displacement demand to the spectral displacement at the effective period for single-degree-of-freedom systems. Simple equations are used to convert back and forth between multi-degree-of-freedom RC wall buildings and equivalent single-degree-of-systems so that relevant engineering demand parameters can be obtained. Consideration is also given to higher-mode effects by adapting existing modal combination rules. The proposed method is applied to several case study buildings, showing promising results in the examination of inter-storey drift ratio and shear forces. The proposed method captures the variation in the distribution of structural response parameters that occurs with variations in structural configuration, intensity, engineering demand parameter of interest and site characteristics. Discussion is provided on possible ways to improve the accuracy of the procedure and suggestions for additional future work.