Abstract: A super large centrifuge foundation was buried in the soft soil. the vibration characteristics research was very necessary and important. The equivalent soil spring model and structure-soil coupling model were established to compare and analyze the vibration characteristics based on different foundation simulation methods. The dynamic time history analysis was carried out base on the white noise excitation, to analyze the influence of the foundation participating mass on the vibration characteristics. The results show that: (1) The first two modes of the super-large centrifuge foundation are horizontal and vertical swings.(2) The vibration modes obtained by different foundation simulation methods are consistent, and the natural frequency difference is within 3%. (3) The foundation participating mass of the first two modes are 1.376 times and 0.998 times the total foundation mass respectively; considering the influence of the foundation participating mass, the vibration response amplitude of the structure is reduced by about 50%, and the peak frequency of the spectrum is reduced by about 2 Hz. The conclusions have guiding and reference significance for the vibration research of the embedded large scale power machine foundation.

Key words: centrifuge foundation, modal analysis, natural frequency, white noise excitation, foundation participating mass