Numerical Simulation Of A Substitute Method In Shaking Table Test For High-rise Tower Considering Soil-structure Interaction Effects

The seismic design method of buildings is based on the rigid ground hypothesis. As the accumulation of disaster data and the in-depth research of structural seismic behavior, it is discovered that the hypothesis does not conform to the actual situation. The seismic design method without regard to soil-structure interaction may waste the construction investment of high - rise buildings and even made hidden danger of safety. Consequently, it's highly necessary for improving and optimizing design to consider soil-structure interaction and check the reliability of structural design through earthquake simulation shaking table test.This paper studies the effect of soil-structure interaction on the tower structure seismic response and proposes the equivalent method that carries out the earthquake simulation shaking table test considering soil-structure interaction. The main work includes:1. This paper briefly introduces the current research situation of the soil-structure interaction and illuminates the existing analysis method of the soil-structure interaction. The merits and demerits of the methods are also commented.2. For the sake of carrying out the tower structure shaking table test considering soil-structure interaction, three dimensional finite element models built are the model considering soil-structure interaction, the model without regard to soil-structure interaction and the model equivalent.3. Modal analysis is performed to get natural frequencies of the 3-dimensional finite element models. Compared to the model without regard to soil-structure interaction, the frequencies of the model considering the soil-structure interaction are extended. The frequencies of the model equivalent are consistent with those of the model considering the soil-structure interaction.4. The results of time-history analysis indicate that: peak displacement, peak acceleration and peak velocity of the model considering soil-structure interaction are smaller than those of the model without regard to soil-structure interaction. The model equivalent could reflect the seismic response characteristics of the model considering soil-structure interaction.5. The spectrum analysis shows that: relative acceleration and relative displacement of the model considering soil-structure interaction are bigger than those of the model based on the rigid ground hypothesis. The result is contrary to the time-history analysis. The main reason is as follows: soil-structure interaction is considered, the frequencies extend, seismic influence coefficient becomes smaller, correspondingly, the earthquake action is smaller, however, the decrease of the structural stiffness is so obvious that the result is opposite.6. This paper brings forward the equivalent method which carries out the tower structure shaking table test considering soil-structure interaction. The numerical simulation results verify that the equivalent method is reasonable and feasible.