分层土中群桩的竖向和摇摆动力阻抗计算

采用动力文克尔地基梁模型,在研究两桩竖向动力相互作用时,建立被动桩的运动方程,求得均匀土中竖向动力相互作用因子的解析解。在各分层土中建立单桩竖向振动微分方程,利用各分层土之间桩身的连续性条件和桩顶、桩底边界条件,求解单桩振动方程。采用三步法计算分层土中桩基竖向动力相互作用因子,结合单桩竖向动力阻抗和相互作用因子求解群桩竖向和摇摆动力阻抗。通过算例分析,得到一些有意义的结果和结论。

THE VERTICAL AND ROCKING IMPEDANCES OF PILE GROUPS IN LAYERED SOILS

With the hypothesis of “Beam-on-Dynamic-Winkler Foundation”, the motion equation of the passive pile is established in studying the vertical interaction of two piles, and the closed-form solution of dynamic interaction factor in homogeneous soil deposits is obtained. The differential equations of single pile for vertical vibration in different soil layers are established. According to the continuity condition of pile between different soil layers and the boundary conditions at the pile top and bottom, the solution of the differential equations can be obtained. A three-step method for calculating the dynamic interaction factors of the pile embedded in layered soils is proposed. Then the impedance of single pile and the dynamic interaction factors are used to calculate the vertical and rocking impedance of pile groups. Through theoretical analyses of practical problems, some useful results are obtained and conclusions are drawn.