非饱和土中端承桩纵向振动问题简化解  

SIMPLIFIED SOLUTION FOR VERTICAL VIBRATION OF AN END BEARING PILE EMBEDDED IN UNSATURATED SOIL

作　　者：张智卿[1] 王奎华[2] 李强[3] 卢萌盟[2] 

机构地区：[1]浙江树人大学城建学院,杭州310015 [2]浙江大学软弱土与环境土工教育部重点实验室,杭州310058 [3]浙江海洋学院土木系,舟山316004

出　　处：《工程力学》2010年第5期159-165,204,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(50879077);浙江省科技厅优先主题重点项目(2007C13065);浙江省教育厅2009年度科研计划项目(Y200909351)

摘　　要：基于单相流固结理论与Bishop有效应力原理,研究了单相流条件下非饱和土中端承桩的耦合纵向振动问题。建立了简化条件下非饱和土体的动力平衡方程,通过引入拉普拉斯变换和势函数对此方程进行解耦,并采用算子分解理论及分离变量法求得土体纵向振动位移形式解。依据桩土系统的边界和衔接条件,进而得到了桩顶动力响应的闭合形式解,并研究了主要参数对桩顶速度导纳和速度时域响应的影响。结果表明,桩长径比和桩土模量比对桩顶动力响应有着显著的影响,而吸力折减系数对其基本上没有影响。Based on one-phase flow consolidation theory and Bishop＇s effective stress principle,the dynamic response of an end bearing pile embedded in unsaturated soil and subjected to a vertical load is theoretically investigated. The simplified dynamic equilibrium equation of the unsaturated soil is established at first. Then,Laplace transform and potential functions are introduced to decouple the governing equation of the unsaturated soil. By virtue of the differential operator splitting and variable separation methods,the soil vibration displacement solution with an undetermined constant is obtained. Combined with the boundary and continuity conditions of the pile-soil system,the dynamic response at the pile top is derived in a closed form. Finally,the influences of major parameters on velocity admittance at the pile top and the velocity response in time domain are analyzed. It is shown that the influences of slenderness ratio of the pile and the pile-soil modulus ratio are remarkable but that the influence of reduction coefficient of the suction is negligible.

关 键 词：非饱和土 单相流 桩土相互作用 纵向振动 导纳 

分 类 号：TU473.1[建筑科学—结构工程]