Comprehensive Comparison Of Seismic Microzonation Methods

China is an earthquake-prone country.Intense ground motion and initiated geological hazard are the main causes of casualties and economic loss.Therefore,knowing about seismic environment which research site locates in is better regarded as the important foundation of anti-seismic design to building construction.In order to effectively reduce the disasters caused by earthquake,research area is divided into many zones,and according to the different zones, different seismic fortification criterions and measure are formulated,to improve seismic performance of engineering structure.This is main purpose for seismic microzonation.Seismic hazard analysis regarded as the basis of earthquake micro-zoning is widely used in many aspects about anti-seismic design,and has been mature with the development of computer technology and numerical simulation technology.The method of seismic hazard analysis is also gradually developed and improved.Different seismic hazard analysis are used in the same area,based on that,comparing and analyzing the features of various and the application areas,obtaining the distribution of ground motion parameter in reseach region can supply technology supports to anti-seismic design and strengthening strategy in the practical engineering.Based on the existing seismic hazard analysis method,the paper mainly concludes the following contents:(1) The application of seismic hazard analysis method in engineering anti-seismic design, the two main methods which are usually used in seismic hazard analysis and the aspects of their advantage and disadvantage,application range,uncertain,etc.are introduced,Also a new improved method based on application of modal summation technique seismic hazard analysis is brought in.(2) It is specifically clarified that the application of seismic hazard analysis' deterministic method,probabilistic method and the deterministic method based on the technology of mode superposition in the earthquake micro-zoning.Mainly include,seismic motion condition, division of potential seismic source,fixing parameters of seismic activity,choosing the ground motion attenuation relationship and the contents of every kind of uncertain study.(3) Using the deterministic method of seismic hazard analysis to get the probabilistic analysis calculation result is came up with,calculation result of using deterministic method is compared with the one of using probabilistic method.The seismic hazard analysis of two situations-long period and short period are respectively calculated in the research area using an improved deterministic method based on application of modal summation technique. (4) With the three methods,calculation results in the same area are analyzed,compare with the different calculating ways.Furthermore,seismic hazard is reasonably evaluated in Dalian area,and determine corresponding risk level.