Study Of Different Seismic Zonation Methods

Although most of the seismic zonation work carried out is based on the probabilistic seismic hazard analysis(PSHA)theory proposed by Cornell,there existed obvious differences for models used in different countries.This paper compared seismic hazard analysis methods of different countries and established the corresponding computation model to stimulate the results,which is used to analyze the influence of different model for earthquake hazard analysis.Based on fully analysis of the current research,the work in this paper could be divided into three parts:(1)This part of work compares and analyzes the main differences in China,the United States,New Zealand,Japan earthquake zonation,focus on the impact for hazard analysis which come from potential source zones model.Based on the comparison with seismic zonation method within different countries,we focus on the differences on geometric type of seismic potential source model.Due to the characteristics of China’s seismic activity and geological formations,China seismic hazard analysis method using multi-level seismic potential source model,while the United States zonation method establishes source model with a combination of several types of source model.It is worth noting that a significant different new method is used in PSHA work of Japan.(2)This part of work studies the key technological method of Global Earthquake Model(GEM),especially for the core calculation program.Based on differences in seismic zonation method,we analyze the core parameter along with their influence for results and take reliability test for OQ-engine using standard software quality assurance procedures.Seismic zoning categories in the main potential source zones model of point source,grid source,area source and line source,this paper analyze setting method for parameters of each model.The results indicate that OQ-engine can be used in each calculation model of different seismic zonation.Besides,of all the key calculating parameter,meshing density has an effect on results.(3)Based on the GEM,took Huabei region for example,the seismic hazard for different types source models is computed in this part.There are two types of potential source area division model,the rupture source model and the area source model.These two methods are compared according to the analysis result of OQ-engine analysis.Finally,the seismic hazard maps of the North China region and the risk curve of the selected typical cities were obtained,and the difference between these two potentialsource area model in the zonation method is analyzed and the differences between these two potential source models in the zonation method is analyzed.For the selection of geometry type for seismic potential source,it should be based on comprehensive consideration of seismic data,structural conditions,seismicity and so on.