Stochastic analysis of linear structural systems under spectrum and site intensity compatible fully non-stationary artificial accelerograms

In seismic areas one of the most important problems for engineers is to characterize in the most correct way the future ground motion accelerations. Building codes allow the practitioners to use artificial time-history compatible with a target pseudo-acceleration spectrum. The spectrum compatible seismic accelerations are usually represented by samples of stationary processes, even if it is well know that the ground motion accelerations should be modelled as samples of fully non-stationary processes. Moreover, the spectrum compatible accelerograms are not able to catch the site intensity of seismic events. In this paper methods able to catch the main features of recorded earthquakes, generating both spectrum compatible fully non-stationary accelerograms and artificial fully non-stationary accelerograms compatible with the site intensity of recorded accelerograms, are presented. In order to quantify the influence of the input model on the structural response, several numerical applications will be carried out and the results will be compared with the Monte Carlo simulation method.