框架-核心筒结构与地基基础动力相互作用振动台试验研究

运用相似关系理论对某超高层框架-核心筒结构与地基基础进行了模拟地震振动台试验，以研究结构-地基基础动力相互作用对结构地震反应的影响以及柔性地基的减震效果。在试验基础上，对结构的振型和上部结构各层的最大位移进行了计算和分析，得到了结构的振动特性和动力响应。同时，还与相同加载条件的刚性地基结构模型的模拟地震振动台试验结果进行了对比。结果表明：柔性地基与上部结构相互作用改变了上部结构的振动特性和动力响应；结构的地震反应不仅与输入加速度峰值大小有关，还与输入的地震波的频谱特性有很大关系；柔性地基参与工作在地震作用强度较小时表现为对地震的放大作用，当地震作用强度达到一定大小时才会对上部结构有减震效果，而且地震作用越强，效果越好。研究结果可为超高层建筑结构设计及其与地基基础的动力相互作用的研究提供参考。

Shaking table tests on dynamic interaction of frame-core tube structure and subgrade

The shaking table test of a super high-rise frame-core tube structure was carried out using similitude theory to study the earthquake responses and damping effects of structure-base-soil interaction system. Vibration characteristics and dynamic responses were obtained by calculating and analyzing the mode shapes and maximum displacement of each floor. Meanwhile, the influence of interaction on structure and the earthquake responses of structure on rigid foundation were acquired by comparing the model test results of the structure which was built on rigid foundation and interaction system under the same load condition. The results show that the dynamic interaction has great influence on both vibration characteristics and dynamic responses of superstructure, and the seismic responses of the structure are not only related to the input acceleration peak but also to the form of seismic wave. Dynamic interactions amplify the earthquake action in small earthquakes, and weaken the earthquake action when the intensity of earthquake reaches a certain size. The results will be useful for the design of super high-rise buildings and study on the dynamic interaction of structure and subgrade.