SHAKER: A selector of consistent and energetically equalized natural ground motions using the Italian earthquake database

Input motion set selection for nonlinear dynamic structural analysis is commonly based on spectral compatibility, obtained through the uniform scaling of natural signals. Due to the aleatory nature of the expected time history, alone spectral compatibility requirement appears very weak to guarantee scaled ground motions that suit local seismic hazard. Magnitude-Distance interval pairs to control selection and scaling factor thresholds do not always provide input motions with adequate energy levels. In order to tackle these critical issues, a novel computer aided selection method based on consistency analysis to provide conservative energy levels has been devel oped. The method equalizes the ground motions subject to the spectral compatibility process to the modified Housner Intensity of the hazard spectra. A multi-parametric consistency analysis based on statistic confidence is performed on the equalized (by uniform scaling) ground motion set by comparing it with the larger regional natural dataset on the same Magnitude-Distance pairs. The consistency analysis involves multiple ground motion parameters taken into relation with the focal mechanism too. Sensitivity tests show the capability of the method to reach high spectral compatibility joined with high consistency degrees by multi-parametric calibration. Compared with the traditional ones, this method also shows greater performance in composing ground motion sets close to real occurrences with a more assorted spectral frequency distribution.