A novel framework for optimal selection of vector-valued intensity measures under mainshock-aftershock sequences considering uncertainties and multi-criteria correlation

Abstract

An optimal intensity measure (IM) can effectively describe the damage potential of ground motions and accurately reflect the relationship between structural responses and seismic parameters, which plays a vital role in earthquake engineering. Although numerous studies have examined ideal IMs for mainshocks, there is limited research on the potential effect of aftershocks on the IM selection. This paper proposes a multi-criteria decision-making (MCDM) framework that addresses the optimal selection of vector-valued IMs for seismic sequences by considering uncertainties and multi-criteria correlation. In this framework, to capture the nonlinear relationship between vector-valued IMs and multivariate engineering demand parameters (EDPs), several novel evaluation criteria are introduced to measure the comprehensive performance of mainshock-aftershock IM vectors. The performance criteria of each vector-valued IM candidate are then treated as a rough concept to handle uncertainties within the selection process. Finally, an advanced selection method is proposed to identify the appropriate alternative in a rough context, which can consider interdependencies among multiple criteria and avoid subjective judgment. The proposed framework is illustrated on reinforced concrete (RC) frame structures, and the effects of the number of aftershocks and the size of IM vectors are investigated to provide further guidance for the IM selection. The results provide valuable insights into the optimal selection of vector-valued IMs in the mainshock-aftershock scenario.