层状地基中单桩扭转振动特性分析

Study on the torsional oscillations of single pile embedded in layered foundation

采用积分变换和Muki的方法求解了层状地基中单桩的扭转振动问题。在分析过程中,首先对基本控制方程进行Hankel变换,建立了单层地基的初参数解答和刚度矩阵,得到层状地基的递推矩阵;然后利用递推矩阵、边界条件和桩-土变形协调条件建立了层状地基中单桩扭转振动问题的基本积分方程并进行数值求解。文末数值算例给出了退化的层状地基中刚性单桩的扭转变形,其结果与已有经典解答吻合良好。同时,并研究了两层地基中单桩的扭转动力响应,分析了桩-土参数对动力响应的影响,所得结论对工程实践和桩基扭转波检测有一定的指导意义。

The torsional oscillations o means of integral transformation and f single pile embedded in layered foundation are investigated by Muki＇s methods. In the analysis, the Hankel transformation is made on the governing equations firstly and the primary parameter solutions and stiffness matrix of single layered foundation are established. The recurrence matrix of layered foundation is obtained. Then, using the recurrence matrix, boundary condition and deformation compatibility conditions, the fundamental integral equation of the torsional oscillation of single pile embedded in layered foundations is established and programmed. At the end of the paper, the torsional responses of the rigid single pile in degenerated layered foundation are obtained and show good agreement with the existing theoretical solutions. Furthermore, the dynamic torsional responses of single pile in two layered foundation are analyzed by numerical examples and the influence of pile-soil parameters on the dynamic response is investigated. The conclusions obtained have some guidelines on practical engineering and torsional wave testing of pile foundation.