饱和土中考虑竖向荷载的端承桩水平振动响应解析解  

Analytical Solution of Horizontal Dynamic Responses of an End-bearing Pile in Saturated Soil Considering Effects of Vertical Loads

作　　者：栾鲁宝 丁选明[1] 瞿立明 

机构地区：[1]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [2]河海大学土木与交通学院,南京210098

出　　处：《防灾减灾工程学报》2017年第3期419-427,共9页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51378177;51420105013);国家自然科学基金高铁联合项目(U1134207)资助;重庆大学中央高校基本科研业务费专项(106112015CDJXZ208805)

摘　　要：考虑土体应力-应变的梯度变化及桩土耦合振动,对竖向荷载作用下饱和土中端承桩水平振动问题进行了理论研究。采用Euler模型模拟桩基,建立了竖向荷载作用下桩基水平振动控制方程;通过势函数解耦土体Biot动力固结方程,并利用Laplace变换和分离变量法得到土体应力和位移解析表达式;结合桩土连续性条件得到桩基位移、内力和桩顶水平动力复阻抗解析解。将退化解与已有文献进行对比,验证了解的合理性。通过算例分析,讨论了竖向荷载和长径比对桩基位移和内力的影响,研究结果表明:竖向荷载和长径比均会使桩身位移和内力发生重分布;在进行桩基水平向承载力设计时,有必要考虑竖向荷载的影响。The lateral dynamic responses of an end-bearing pile considering vertical loads in saturated soil are investigated in this paper.Both the variations of soil stress-strain along depth and the coupled vibration of pile-soil system are taken into account in the derivation.The governing equation of pile is deduced on the basis of Euler Model considering vertical load.The potential functions are introduced to decouple the equations of the saturated soil on the basis of Biot dynamic consolidation theory.The expressions of soil stress and displacement are obtained by the Laplace transformation and variable separation method.Thus,displacements,internal forces and complex impedances of the pile under horizontal vibration are derived on the basis of continuous conditions between the pile and the soil.Comparisons between the degenerative solution with the existing one are carried out to demonstrate its validity.Numerical analyses are presented to study the influences of vertical loads and length-diameter ratios on the displacements and internal forces of the pile.The research shows：vertical loads and length-diameter ratios redistribute the displacements and internal forces of the pile.Vertical loads should be taken into account in the horizontal designation of piles.

关 键 词：饱和土 竖向荷载 水平振动 阻抗 解析解 

分 类 号：TU375[建筑科学—结构工程]