A Comparative Centrifuge Test Study on the Influence of Overlying Seawater on Seismic Response Spectrum

Abstract

In this study, dynamic centrifugal model tests for two homogeneous saturated soft clay sites are designed to analyze the influence of overlying sea water on ground motion. We obtain the response spectrum value and amplification coefficient from the acceleration sensor records. Through comparative analysis, we conclude that with the increase in input peak ground motion, the acceleration response spectrum value at the same depth gradually increases. When the input peak value is small, there is no significant difference between the response spectra with and without water; when the input peak value is large, there is no significant difference in the high-frequency part of the response spectrum value. In the middle- and low-frequency part, the response spectrum value with water is obviously smaller than that without water. The amplitude of the response spectrum of the water-free model gradually moves in the long-period direction, but the water model tends to the short-period direction. In the long-period part, the amplification coefficient of the water model is obviously smaller than that of the water free model.