Comparative Study On Dynamic Response Of Seismic Shaking Table Foundation

Shaking table test is one of the main methods for seismic analysis of structures. For a seismic shaking table, the dynamic response of the foundation is among the key problems. At present, the design of shaking table foundation draws lessons from dynamic machine foundation, for there is no specification for it.Suzhou University of Science and Technology is proposed a three-dimensional six degrees of freedom shaking table, the size of the table-board is 6m×8m. In view of the practical project, a series of comparative study has been taken on to analyze the dynamic response of its foundation. Based on the systematical summary of methods for dynamic machine foundation at home and abroad, the contents of this paper are as follows:1. Refer to design methods of dynamic machine foundation, the design plan of the seismic shaking table foundation has been proposed, its geometric parameters meanwhile calculated.2. To analyze the dynamic response of machine foundations in frequency domain, there are three available methods:the Code for design of dynamic machine foundation, the Laplace-Transform method and impedance method. Having applied the three methods to the seismic shaking table foundation successively, it turns out that the responses in different methods are coincident in higher frequency while divergent in lower frequency and resonance region. Besides, the results show that the foundation could satisfy vibration control requirement.3. Relying on the finite element software ABAQUS, a method is produced to analyze history dynamic response of seismic shaking table foundation, including modeling, artificial boundary selection and dynamic loads applying. After comparative study between numerical simulation results and above results, it turns out that in terms of the maximum acceleration as control objective, with respect to the results of the finite element method, the Code is conservative, impedance method is unsafe slightly, the Laplace-transform method is consistent.4. The sensitivity of shear modulus of soil is analyzed by the finite element method, the results show that:the dynamic response of seismic shaking table foundation and shear modulus is basically a linear relationship.Finally, the full content of the dissertation are summarized and further research work is discussed.