A new energetic based ground motion selection and modification algorithm equation

This paper presents a new ground motion modification and selection procedure to be used for performing the response history analysis of structures. The proposed selection and scaling procedure is based on an energetic comparison in a frequency band. The Conditional Mean Spectrum is used as target spectrum while only the records providing a relevant contribution to the hazard at the site are considered. The set of ground motion with the same hysteretic energy demand is obtained matching the acceleration of the target spectrum at the period of interest Tref and selecting only the scaled spectra having a similar Housner intensity in the period range 0.2Tref – 2Tref. A set of records which are spectrum compatible, having a similar hysteretic energy demand are obtained. This last aspect can be reflected in terms of equal damage level expected on the structure, since the damage parameters coming from the response history analyses present a very low dispersion. As a result, the new energetic approach allows selecting a set of ground motion according to the spectrum compatibility criterion, to the frequency content representativeness and to the consistency of the expected structural damage for the given hazard scenario.