Experimental study on seismic ground motion amplification pattern of soil-structure interaction system

A series of 1 g shaking table tests are performed to investigate the seismic ground motion amplification pattern, including free-field test and soil-structure test. This study outlines two issues. First, for the free-field model, the comparison of both transfer func- tions and natural frequencies between the experimental data and the analytical solutions was made. It is found that the measured transfer functions could reflect the characteristics of ana- lytical solutions on the whole. Second, the influence of the existing of atrium-style subway sta- tion on acceleration responses of soil was emphasized. Two influencing factors were thought to have an important contribution to the seismic ground motion amplification pattern. One is the frequency content of input ground motion and the other is the height of the underground structure, which determined the relationship between seismic wavelength and the size of the structure. This paper only presents the acceleration responses, but the conclusion will also provide a possibility to explain other dynamic responses of soil-structure model. This study also provides preliminary criteria to determine whether the existing of an underground struc- ture can be neglected in the design of a surface structure.