Research On Ground Motion Input Of Seismic Response Of High-rise Building Structures

Earthquake is a serious natural disaster.Moderate to strong earthquakes can cause strong ground motions,which can lead to the earthquake area and the surrounding buildings damage or even collapse.Earthquake also cause serious damage to people’s lives and property.With the popularization and application of theories in the field of earthquake resistance,especially the performance-based seismic design method,and the development of computer technology,the numerical analysis method of structural dynamic time history analysis has gradually become the standard and accurate method for seismic response analysis and seismic performance evaluation of structures.The primary task of dynamic time history analysis is to select reasonable ground motions.Different ground motions caused the different responses of the structure.Therefore,it is necessary to select a group of appropriate ground motions to ensure the results of dynamic time history analysis have less discreteness.Based on the research background,this paper studies the influence of different target spectra and different scaling methods on the dispersion of the analysis results of dynamic time-history analysis,and studies a new target spectrum of Xi’an.Firstly,studied the primary condition of ground motion and established the relationship between design seismic group and ground motion parameter,and given the primary condition range of ground motion parameter.Secondly,the target spectrum is studied,including the PGA target spectrum and the code target spectrum.The PGA target spectrum establishes the bridge between seismic parameters and the seismic fortification target through the peak acceleration attenuation relationship,and the standard target spectrum is determined according to the seismic fortification target,site conditions and basic period of the structure.scale method includes matching at fundamental period scaling method,average spectral ratio scaling method,equal spectral intensity scaling method,minimum squared error scaling method and least moving average scaling method.The time-history analysis of a framed-tube structure is performed using the ground motions selected and scaled by different methods.The displacements,inter-story drift angle,and the inter story shear force are analyzed for dispersion.The results show that the PGA target spectrum is larger than the code target spectrum,least moving average scaling method is less sensitive to different target spectra,and the most suitable method for different contrast targets and different target spectra is different.Compared with other scaling methods,the least moving average scaling method is a more suitable method.