层状地基中沉箱加桩复合基础的水平-摇摆振动

Lateral vibration of caisson-pile composite foundation in layered soils

对沉箱基础底部加桩之后侧向动力性能的改善问题进行了研究。首先,通过沉箱和群桩两部分在界面处的内力平衡和位移协调条件建立了复合基础的水平–摇摆振动方程,其中沉箱部分的振动方程采用动力Winkler地基模型根据受力平衡条件建立,群桩部分的振动特性则依据既有文献的研究成果。然后,对沉箱振动的动力Winkler地基模型参数进行了研究,得到改进的表达式。最后,通过算例研究了层状地基中复合基础的水平–摇摆振动问题,验证了沉箱下群桩明显地改善了基础的动力性能。

The improvement of vibration characteristics of caisson foundation due to the piles added at the bottom is studied.Firstly,dynamic equilibriums for lateral vibration of caisson-pile composite foundation are created through the displacement coordination and internal force equilibriums at the interface between the two parts of the caisson and piles.Vibration equilibriums for the part of caisson are created by external force balance with the utilization of dynamic Winkler model,and vibration characteristics of the part of piles are defined by the existing literatures.Secondly,the coefficients of dynamic Winkler model in vibration of caisson are studied,and improved expressions are derived.Finally,taking a composite foundation in layered soils as an example,the improving effect of piles under the caisson is observed.This example shows that the piles under the caisson can improve the dynamic performance of the foundation significantly.