桩与粘性阻尼土耦合纵向振动时桩顶时域响应研究

Time Domain Axial Response of Dynamically Loaded Pile in Viscous Damping Soil Layer

假设桩周土层为均质粘弹性体 ,土材料阻尼为粘性阻尼 ,从轴对称角度 ,对任意激振力作用下弹性支承桩与土耦合纵向振动时的桩顶时域响应进行了理论研究 ,求得桩顶位移阻抗函数解析解 ,给出半正弦脉冲激振力作用下桩顶速度时域响应半解析解。基于所得解对桩土系统的振动特性进行了分析 ,重点探讨了桩侧土粘性阻尼的特殊影响 ,得到若干新的结论 ,最后将理论解与现场工程桩实测曲线进行了拟合对比 ,表明本文理论结果能够更好地反映客观实际。

Assuming that the soil is uniform linear visco-elastic layer with viscous type damping, the time domain axial response of dynamically loaded pile in the soil layer is theoretically investigated. And the corresponding solution of the displacement and velocity response function at the pile top end in frequency domain is obtained in a closed form. Then, by means of invert Fourier transform, a quasi-analytical solution of velocity response of the pile in time domain subjected to a half sine wave exciting force is obtained. Based on the solution, a parametric study is conducted to determine the main features of the soil-pile interaction, and the special influence of viscous damping of soil layer is also discussed here. At last, it is proved that the theoretical curves are in good agreement with that obtained from the field measurement.