Influence Of Earthquake Records Selection On The Dynamic Response Of Stormproof Playground

The time history analysis method is an important means to evaluate the seismic performance of structures.The first step of the analysis is to determine the design ground motion.A reasonable ground motion input is a necessary condition to ensure the reliability of the time history analysis result.A variety of methods for selecting ground motion records have been proposed,but most methods only consider the spectral characteristics of horizontal one-way or two-way ground motions,and do not fully consider the spectral characteristics of vertical ground motions.Large-span spatial structures and high-rise buildings are often sensitive to vertical earthquakes,and the impact of vertical earthquakes on the structure cannot be ignored.In the selection stage of ground motion records,if the input vertical ground motion spectrum characteristics of a wind-rain playground type mixed structure with a large-span spatial structure roof is not restricted,the seismic response of the structure may be overestimated or underestimated,resulting in structural failure.The economy may be insecure.Therefore,this paper studies the input of three-way ground motion records.The main work is as follows:(1)In order to evaluate the applicability of different wave selection methods,this paper selects 55 sets of three-way ground motion records from the Pacific Earthquake Database according to the magnitude,epicenter distance,and site conditions.The statistical response spectrum of these records is required to correspond to the target site fortification intensity.The response spectrum is statistically consistent within a certain period range.The average structural response calculated by 55 sets of records was taken as the "predicted value".The statistical response spectra of 55 groups of ground motions are taken as the target spectra.The selected ground motion record input structures selected by different wave selection methods and their calculation results are statistically analyzed.The coefficient of variation and relative error are used to measure the effectiveness and reliability of each method.(2)Through the analysis of the seismic performance of the grid roof-concrete frame hybrid structure of the wind and rain playground,the sensitivity of the structure to horizontal and vertical earthquakes is studied and judged.In order to ensure that the selected ground motion records can reach a certain level of seismic hazard in both horizontal and vertical directions,this paper proposes an improved wave selection method that controls both the horizontal and vertical ground motion spectrum characteristics(The horizontal control refers to the ground motion matching principle specified in the American standard ASCE7-10),and gives the specific operation process of the wave selection method.(3)Use Midas-Gen to analyze the dynamic time history of the two types of mixed structure of wind and rain playground.The improved wave selection method proposed in this paper and the calculation results of the single-period point and dual-frequency wave selection methods(structure base shear force,inter-story displacement angle,grid support displacement,grid member axial force,grid vertical maximum Displacement)for comparison.The results show that the relative error and coefficient of variation of the structure response obtained by the improved wave selection method are smaller than the single-period and dual-frequency wave selection methods,and the calculation results are more reliable and effective.