频率相关域的桩基-结构竖向-水平振动特性分析

导出了一种可考虑土的分层以及桩顶轴向力参与作用的计算土介质中群桩动力相互作用因子的方法,进一步增强了S-R简化模型的应用效能.利用子结构理论,可计算任意构型、桩数、土层属性下的群桩结构系统动力反应,其计算工作量较小,便于工程应用.通过一桥梁墩基结构的地震反应分析表明:考虑竖向振动附加影响的水平激振作用会产生相当的附加变位,致使水平群桩阻抗效应减少;同时桩间动力相互作用影响也较单一水平力作用时有明显规律性的增强;桩土子结构的柔性参与在一定程度上可降低体系水平动力反应.

A Horizontal Vibration Study on Pile-soil-structure under the Effect of Frequency-dependent Axial Forces

A new method for the study of lateral dynamic interaction factors was presented by considering the participation of axial loads on pile-head in layered-soil in order to further extend the applications of the simplified S-R model in engineering practice. By means of substructure theory, the dynamic response of pile-groups-structure characterized by random configuration, pile number, soil properties, etc., can be fulfilled with less cost-time than other numerical methods. With the computation for a bridge-pier base suffering earthquake action, it is indicated that additional displacement will engender the effect of vertical oscillation, which results in the decrease of horizontal impedance effect of pile-groups, and the influence of pile-soil-pile interaction is markedly enhanced over that under single horizontal vibration. In general, the horizontal dynamic response of a whole system will be reduced due to the relative flexible participation of pile-soil subsystems.