土-桩-钢框架结构动力相互作用特征研究

利用振动台模型试验和有限元数值模拟的方法对土质地基-群桩-钢框架结构体系动力相互作用的规律和特征进行研究，并讨论了基桩长径比对于体系动力相互作用特征的影响。试验地基土体模型为均匀粉质黏土，剪切波速约为213 m/s；群桩基础由9根长2.0 m、直径0.1 m的基桩3×3对称布置；上部结构模型简化为三层钢框架结构。本文研究结果表明：土-桩-钢框架结构体系的阻尼比相较固定基础情形有所增加，输入相同地震动时其地震反应小于固定基础情形；动力相互作用体系中运动相互作用的贡献与惯性相互作用相当，不应忽略；随着基桩长径比的增大，运动相互作用增大，钢框架结构的加速度反应增大。

Research on Dynamic Interaction Characteristics of Soil-pile-steel Frame Structure

The laws and characteristics of dynamic interaction of soil-pile group-steel frame structure system were studied by shaking table model test and finite element numerical simulation, and the influence of pile aspect ratio on the dynamic interaction characteristics of the system was discussed. In the test, the soil model was uniform silted clay, and the shear wave velocity was about 213 m/s; The pile group foundation was composed of 9 piles with a length of 2.0 m and a diameter of 0.1 m, which were a 3×3 symmetrical layout; The superstructure model was simplified as a three story steel frame structure. The results show that comparing with fixed foundation structure, the damping ratio of the soil-pile-steel frame structure system is increased, and its seismic response is less than that of the fixed foundation structure under the same seismic input; The contribution of the kinematic interaction in dynamic interaction system is equivalent to that of inertial interaction which should not be ignored; With the increase of pile aspect ratio, the kinematic interaction and acceleration response of the steel frame structure increase.