径向非均质土中平面应变模型的精度及适用性研究

Study on the accuracy and applicability of plane-strain model in radial-heterogeneous soil layers

对径向非均质土体中复刚度传递的多圈层平面应变模型和多弹簧串联的多圈层平面应变模型的精确程度及其适用性进行研究,根据精确的三维连续介质模型得到的结果,与上述两种简化模型进行效验对比。首先对桩土接触面上的复剪切刚度的实部和虚部进行对比,然后分别在多种工况条件下,对采用上述两种平面应变模型时桩顶动力响应进行比较分析。结果表明,复刚度传递的多圈层平面应变模型在绝大多数情况下具有足够高精度,而采用多弹簧串联的多圈层平面应变模型的结果误差较大,这为径向非均质土体中平面应变理论的应用提供了重要的理论依据。

The accuracy and applicability of complex stiffness transfer plane-strain model and series connection spring plane-strain model in radial-heterogeneous soil layers are presented. From the results of a precise three-dimensional continuum model, comparative studies on the two types of plane-stain models are conducted. The soil complex stiffness at pile-soil interface is studied. Comparisons of responses in the frequency domain and the time domain are obtained under various construction conditions. The study proves that the differences between the continuum model and the complex stiffness transfer plane-strain model are generally small, and the accuracy of the complex stiffness transfer plain-strain model is sufficient. It is also found that the accuracy of the series connection spring plane-strain model is inadequate.