Abstract: In order to reveal and master the ground motion characteristics of marine soft soil site, to provide scientific and reliable design response spectrum as the basis for seismic design of marine engineering, better serve the engineering anti-seismic design, in this study, a centrifugal model of marine saturated soft soil site covered with water was designed and constructed. Five sets of shaking table tests were carried out under a 100g centrifugal environment, and the acceleration results at the seabed surface under different seismic input conditions were obtained; Three commonly used design spectrum fitting calibration methods were used to fit and regress the acceleration response spectrum, and the fitting parameters obtained by different methods were compared and analyzed. The results show that:There is a big difference between the design spectrum and the test response spectrum of the current building seismic code in my country, the characteristic period value of the calibrated design spectrum is obviously small, so there is a design risk for the seismic resistance of long-period projects; While the design spectrum and test response spectrum based on the U.S. seismic code have good consistency, the characteristic period of the calibrated design spectrum is relatively reasonable, but the design spectrum platform value is obviously too small, therefore the engineering is unsafe either. In contrast, the calibration results of design spectrum calibration proposed by Bo Jingshan research team are more reasonable, and the characteristic period of design spectrum is in good agreement with the test response spectrum.

Key words: marine saturated soft soil sites, dynamic centrifugal model tests, acceleration response spectra, design response spectrum calibration