Amplitude variation of earthquake ground motion with depth

The amplitude variation of ground motion with depth is an important consideration in characterizing ground motion for embedded structures. In this paper, based on the Surface and downhole data from Hosokura Mine Array of Japan and CSMIP Geotechnical Arrays of U.S.A., a study on earthquake ground and sub-ground motion is conducted. According to the site condition, the arrays are classified into three types. In addition, earthquakes in each site are classified into three levels according to the earthquake magnitude. In the end, the amplitude ratio curves with depth of each earthquake level are established as a result of a nonlinear regression analysis of the data mentioned above.