Engineering ground motion selection based on displacement-spectrum compatibility

In this paper we address the selection of displacement-spectrum compatible natural accelerograms for displacement-based seismic design and assessment by nonlinear dynamic analysis. This involved: i) the definition of a target displacement spectrum for Italian sites, that fits the results of probabilistic seismic hazard analyses both at short and at long periods, ii) the construction of an ad hoc high quality strong ground motion database, namely SIMBAD, and iii) the development of the software REXEL-DISP to select suites of real accelerograms compatible with target displacement spectra. Illustrative applications of REXEL-DISP are presented to underline some interesting features of displacement-based ground motion selection, namely the good performance of unscaled records and the possibility to achieve broadband spectral compatibility, given the availability of tools for computer aided record selection.