基于经典的平面应变假定,将土体假设为若干个相互独立的薄层,对饱和土地基中现浇大直径管桩水平振动频域特性进行了理论研究。首先通过引入势函数对土体动力固结方程解耦,采用Laplace变换和分离变量的方法求得了桩周土及桩芯土频域响应解析解,进而利用桩土完全耦合的条件得到桩振动响应解,给出了桩顶复阻抗解析表达式。将本文解完全退化到实心桩的解与已有理论解对比,验证了本文解的合理性并阐明两解的区别。通过参数分析,得到了桩长以及桩半径等参数对复阻抗特性影响的规律。
Based on the classical plane strain assumption, considering the soils as a series of independent thin layers, the frequency-domain horizontal dynamic response of a cast-in-situ large-diameter concrete pipe pile in saturated soils is investigated. The potential functions are employed to decouple the consolidation equations of the soils, the analytical solutions of the outer and inner soils in frequency domain are obtained by the Laplace transform technique and the separation of variables. Under the assumption of perfect contacts between the pile and both the outer and inner soils, the response of the pile is derived and its complex impedances are obtained. The derived solution is compared with that of a solid pile to verify the rationality, and the difference between the two solutions is illustrated. The effects of the pile length and section radius on the complex impedance of pile top are analyzed.