液化土群桩基础水平地震力振动过程中桩侧摩阻力和桩端摩阻力的变化分析

摘要

研究了液化土桩基体系在水平地震力作用下桩侧摩阻力和桩端摩阻力的变化.通过振动台试验验证了MIDAS-GTS有限元分析软件的可行性;并通过有限元分析,得到3D、3.5D、4D三种工况下的沉降时程和振动不同时间桩基的荷载—沉降(Q-S)曲线,分析两曲线结果,依据相关文献对振动过程中桩侧摩阻力和桩端摩阻力进行了求解.初步提出当地基土存在液化土层,考虑动载作用时的桩基竖向承载力的修正公式,为相关设计提供一定参考.%The variation law of pile-side friction and pile-end friction in horizontal seismic vibration process of piles foundation in liquefiable sandy soil was studied.Firstly,through shaking table tests,the feasibility of MIDAS-GTS finite element software was verified.Through FE analysis,the settlement time histories of the piles foundation under 3D,3.5D and 4D working conditions and its load-settlement (Q-S) curves during different vibration time durations were obtained.Based on relevant literatures,the curves were analyzed and the pile-side friction and pile-end friction were calculated.When the piles foundation was in a liquefiable soil layer,the modified formula for the vertical force-bearing capacity of the piles foundation under dynamic load was proposed to provide a reference for the relevant design.