A methodology for the identification of design earthquake inputs

In recent years, Performance Based Seismic Design (PBSD) has played a central role for research works in the field of seismic engineering. The core idea of the PBSD is the probabilistic assessment of the structural performances due to seismic action [Bertero and Bertero, 2002, Moehle and Deierlein, 2004, Zhang et al., 2004]. From a practical point of view, following the PEER framework [Cornell and Krawinkler, 2000], this assessment can be achieved through an articulated procedure which can be summarized in the following subtasks [Zhang et al., 2004]: · Probabilistic Seismic Hazard Analysis (PSHA) or simply Hazard Analysis (HA); · Probabilistic Seismic Demand Hazard Analysis (PSDHA); · Probabilistic Seismic Capacity Analysis (PSCA) also called Fragility Analysis; · Seismic Reliability Analysis (SRA). This paper focuses mainly on the correct identification of the dynamic inputs (“bins” as defined by [Giovenale et al., 2004] or “EPI groups” as defined hereafter by the authors) to be used in the PSDHA subtask. In detail, the paper introduces a general framework (“methodology for EPI group creation”) for the rationally-organised treatment of the latest contributions in terms of ground motion parameters which have a substantial effect upon the structural response. Among the factors taken into account in the proposed methodology for the correct identification of the EPI group, we mention the use of vector-valued IMs [Baker and Cornell, 2005, Trombetti et al, 2003], the recently proposed parameter “epsilon” (as obtained by disaggregation analysis [Baker and Cornell, 2005]), magnitude “MS”, site to epicentre distance “R” and relative number of near field records.