分层土中单桩和群桩的水平动力阻抗计算

THE LATERAL IMPEDANCES OF SINGLE PILE AND PILE GROUPS IN LAYERED SOILS

采用文克尔地基梁模型,在各分层土中建立单桩水平振动微分方程,利用各分层土之间桩的连续性条件和桩顶、桩底边界条件,求解单桩振动方程。结合单桩动力阻抗和相互作用因子求解群桩水平动力阻抗。根据能量守恒原则,利用桩的水平静载变形曲线求取分层土等效为均匀土层的参数,提出将分层土等效化为均匀土近似计算单桩和群桩水平动力阻抗的方法,通过算例分析,得到一些有意义的结论。

With the hypothesis of 揵eam-on-Winkler foundation, the vibration differential equations of single pile in different soil layers are established. Combining with the continuum condition of pile between different soil layers and boundary condition of pile on the top and bottom, solution of the differential equations is obtained. The single pile impedance and dynamic interaction factor are used to calculate the impedance of pile group. An approximate method for calculating those impedances is also proposed. In this method, layered soils are replaced by an equivalent homogeneous soil. The parameters of equivalent homogeneous soil are obtained by energy-conservation principle and the deflection figure of pile induced by lateral static load at pile top. Finally, some useful conclusions are presented through theoretical analysis of practical problems.