Effects Of The Thickness Of Overburden Layer On Peak Accelerations Of Ground Motions And Response Spectra

The ground motion characteristic of site surface is influenced by focal mechanism, seismic wave transmission, especially for the effect of local site conditions. Many scholars put a strong focus on the effect of cover thickness exerted on ground motion characteristic of site surface. In the thesis, the author carries out some researches of this kind of issue based on the former researches and completes the following tasks after the preliminary exploration.1.The studies of the thickness of overburden layer on peak accelerations of ground motions and response spectra were systematically studied and summarized.lt points out the train of thought and the related calculation parameters.2.Introducing the principle of the computer program for one-dimension equivalent linearization method of soil layers seismic response analysis in earthquake engineering field.3.Select four types of soil, such as clay, silt, sand and gravel to build140single homogeneous soil profiles. Then make a research on the effect that overburdens thickness exerted on the seismic response of the site soil surface. The author also puts forward some considerations about the selecting input earthquake waves, soil nonlinear parameter, and calculation model of site construction.4.Make profiles according to different cover thickness of homogeneous clay, silt, sand, gravel site coverage of the layer thickness profile. Input synthetic ground motion time histories with the peak of50gal、100gal、150gal、200gal、300gal; utilize one-dimensional equivalent linear wave method to calculate the seismic response of soil surface, then make a statistical analysis of calculated surface peak acceleration, value of the acceleration response spectrum platform, and characteristic period.In the end of this thesis, the main work and results are summed up.And the following work and future study are pointed out.