The Research On Different Site Soils Influence On Ground Motion Parameters

Kunming is located at between Xiaojiang and Pudu River fault zone, an area of high earthquake frequency. Seismic fortification criterion regionin of Kunming is 8 degree, the seismic fortification criterion regionin of Dongchuan, Xundian is 9 degree. Recently, most areas of Yunnan Province occurred earthquake, crustal movement frequently. Meanwhile, Kunming, as the largest population in Yunnan province, which occurring earthquake,will give located people causing huge losses and other economic assets.Therefore, seismic researching projects and other aspects research on Kunming,has very importantly significance. Currently,many scholars has been researching on seismic isolation technology,and the achievement has been applied to Changshui airport, Yuxi buildings and other projects,getting effectively acts. But as passive seismic control technology, seismic isolation technology has high costs, rubber isolation bearings replace complex, increase Tg values and other characristics,it is not ideal effect on flexible structure and soft foundation use this technology,and may take structure and foundation resonance,giving structure more damage.Based on Seismic Design of Buildings (GB50011-2010) choose motion parameter values to calculate dynamic response,as local topography, response and fortification values may be high or low actual situation. Soil structure, soil depth, and other venues will have an impact on ground motion parameters. According to Kunming geothermal Cenozoic basement structure and thickness contour map, collecting different cover thickness layer geotechnical investigation report, establishing one-dimensional horizontal layered soil, based on equivalent linearization method analysis seismic response, to research different area of thickness soil affecting peak ground acceleration,response spectrum and Tg, to realise variation of peak ground acceleration of seismic waves in the soil, to give recommended value of the amplification factor, characteristic periods at each region.By statistical results showed:Ⅱ soil site, under the frequently earthquake,its amplication factor is 1.374～1.875;under Fortification earthquakes, its amplication factor is 1.382～1.897; under rare earthquake.its amplication factor is 1.538～2.11. Ⅲ soil site, under the frequently earthquake,its amplication factor is 1.22～1.671;under Fortification earthquakes, its amplication factor is 1.303～1.702; under rare earthquake,its amplication factor is 1.423～1.871.Peat, as a special soil in Kunming, could bring negative effect on bearing capacity of foundation. The articl also take the dynamic triaxial shear test, researching stress-strain and dynamic strength curves.Analysis seismic response on single Peat soil. When the thickness is 2, 3,4m, research the attenuation of peak acceleration of ground motion.