| With the rapid developments of strong ground motion databases all over the world and the software for structural analysis worldwide, the nonlinear dynamic time history analyses have been widely used in ciivl enginreering. However, the research on the selection and scaling of ground motion records has not been paid much as attention in China. As we know, the ground motions used in nonlinear dynamic analyses should represent the hazard levels of the building site where the structure is located. Therefore, in this thesis, the selection and scaling of ground motion records are combined with the probabilistic seismic hazard analysis(PSHA). First of all, the deaggregation of PSHA is accomplished based on Arc GIS Engine. According to the obtained results, the senario earthquakes are calculated. Subsequently, the uniform hazard spectrum(UHS), the senario-earthquake based spectrum(SEBS) and the conditional mean spectrum(CMS) are calculated, respectively. These spectra are then selected as the target spectra to which the response spectra of ground motion records to select are matching. Five methods of scaling are adopted. To evaluate the influences of different selecting and scaling methods, four inelastic performance-based parameters of the ideal elasto-plastic single degree of freedom(SDOF) system are chosen with the aim to select the seismic ground motion records suitable to the Xi’an region.The main contents of this thesis are as follows:1) The deaggregation of PSHA in Xi’an region. Based on the discretization algorithm of PSHA, the deaggregaion is completed by dividing the potential seismic sources to small units whose sizes are 10km*10km, in the Arc GIS Engine. In this part, the contributions to the hazards of some sites of each unit are calculated. Based on the deaggregation results, the seismic zone maps including the information of scenario earthquakes of each potential seismic sources, as well as the scenario earthquake of each control point, are fulfilled.2) Selection and scaling of ground motion records in Xi’an region. Based on the scenario earthquake, the initial ground motion database in Xi’an region is built from the PEER Strong Ground Motion database. Considering the correlations of spectral accelerations of different periods, the conditional mean spectra are calculated. Taking the uniform hazard spectra, the scenario spectra and the conditional mean spectra as the target spectra, the ground motin records suitable to the Xi’an region are selected, and then, five scaling methods, which includes single point scaling and multi-points scaling in some certain interval periods, are used to match the target spectra.3) Evaluation of methods for selecting and scaling of ground motion records. The results of selection and scaling of ground motion records are input to the ideal elasto-plastic single degree of freedom(SDOF) system. Four parameters, namely, the maximum inelastic displacement, the ductility factor, the damage index, and the inelastic displacement ratio, are used to conduct the evaluation, and finally the influence rules of the different selection and scaling methods are deceived.Through the study of this thesis, the results of PSHA in Xi’an region are improved and complemented, and reliable supports are provided for the calculation of the senario earthquakes in Xi’an. Taking the UHS from PSHA, the SEBS and CMS from the deaggregation of PSHA as the target specra for selection of ground motion records in Xi’an region, using five kinds of scaling methods, the obtained ground motin records have provided valuable, supportable and referencial ground motin inputs for analysis and design of pratical engineering structures. |
