The Effect Of Site Types On Platform Value Of The Design Response Spectrum

Determination of the design response spectrum is the basis of seismic design, also is one important method to determine earthquake loading, response spectrum platform value is one of the important parameters to difine the design response spectrum shape.Seismic design of buildings (GB50011-2001) in our country when we determine the value of design spectrum platform (the maximum seismic effect coefficient), the only effects considered is the basic intensity (or the design of the basic seismic acceleration), have nothing to do with the site conditions, destructive earthquakes and recent seismic studies show that the the shape of response spectrum is related not only the intensity of ground motion, but also the closely related site. Following experience with earthquake damage and the accumulation of earthquake records with information on site conditions, the effect of design response spectrum platform value by site has aroused wide attention and research interest, is one of the hot issues of geotechnical earthquake engineering research at present. This paper on the base of some studies carried out some research on this issue, has completed the initial exploration and got the following major tasks.1. The studies of the site effect on the design response spectrum platform value were systematically studied and summarized, the method of determining the response spectrum value platform is expounded in detail.2. Tthe hundreds of site borehole data in the chinese mainland were studed, on this basis, a number of representative and typical site profile were selected orconstructed, and According to the method of the seismic design of buildings site classification is conducted, this profile is as calculated profile,at the same the corresponding computational model and the parameters were determined,the calculated modes are both meaning and representative works. The study of the site on response spectrum platform value use this method which is the current widely used the soil seismic response analysis in engineering and combine with the selected type of soil profile.3. The different sites and ground motion input effects on the design response spectrum platform value were reseached. Statistical analysis platform values were given by four different sites and earthquake input, the relations of different site response spectrum platform and ground motionwere given by linear regression analysis.4. In this paper, as the representative site in Xichang City Earthquake Disaster Mitigation Planning a example, the calculation model and related parameters were determined by engineering drilling and geotechnical test, the input ground motions were determined by probabilistic seismic hazard analysis, the design spectrum platform values of a 50-year probability of exceedance of 3%, 10% and 63% were given. And the results compared with the third chapter, draw some meaningful conclusions about Xichang City Earthquake Disaster Mitigation Planning.Finally, this article summarizes the research work and research issues are briefly discussed and proposed in future.