Study On The Representative Site Parameters Of Ground Motion Variability

The geologic structure of the site,the terrain and topography,and the complex geological structure of the ground are very important to the ground motion.T he difference of the ground motion caused by the site can cause the difference of the earthquake damage of the different sites.How to estimate the difference of complex site in the design of large-scale earthquake disaster prediction and seismic design,and how to estimate the distribution of ground motion parameters under the action of strong earthquake in the future are all difficult problems to be solved.On the basis of predecessors' work,this paper explores the influence of site characteristic paramete rs on the dynamic changes of seismic sites by means of numerical simulation,and puts forward the site characteristic parameters which characterize the change of ground motion,and then use the method of numerical simulation as the object of study.The results are applied to the prediction of ground motion in complex area.The results of this paper can provide theoretical basis for regional ground motion prediction,and provide important basic data for the development of regional long-term development planning and seismic design of buildings,which has practical application value in the field of earthquake disaster reduction.The main achievements of the paper are as follows:1.A total of 56 horizontal field models were constructed,and three seismic le vels were selected for the zone of fortification intensity VIII.The one-dimensional equivalent linearization method was used to study the variation law of peak acceleration of different types of earthquakes under three kinds of earthquakes.The peak acceleration amplification coefficient K and the quantitative relationship between the parameters Vse and Vs30 of the ground surface movement.2.The finite element model of the undulating site is established by using ABAQUS software,and the variation characteristics of the peak acceleration and spectral characteristics of the undulating site under different ground motions are discussed.It is pointed out that the undulating site is combined with the terrain and soil,and its amplification effect is about the terrain and soil The product of the amplification effect.3.Based on the analysis of the ground pulsation and borehole data,the calculation formula of the excellent period and the equivalent shear wave velocity and the thickness of the cover layer is give n,and the thickness distribution of the cover layer in the study area is obtained.Graph,equivalent shear wave velocity Vse and Vs30 distribution.4.Vse and Vs30 are used as the characterization parameters of the seismic dynamic change of the site.The ground load of different sites in the Li County is predicted by the quantitative relationship between the peak acceleration amplification coefficient K and Vse and Vs30,and the results are calculated by one-dimensional equivalent linearization verification.The results of the study provide reasonable ground motion parameters for seismic and disaster prevention and mitigation in the area.