基于Pasternak地基模型的H(t)-T受荷桩受力变形分析  

Force and Deformation Analysis of H(t)-T Loaded Pile Based on Pasternak Foundation Model

作　　者：江杰[1,2,3] 陈丽君 柴文成 艾永林[1,2] 欧孝夺 龚健 JIANG Jie;CHEN Lijun;CHAI Wencheng;AI Yonglin;OU Xiaoduo;GONG Jian(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures,Guangxi University,Nanning 530004,China;Guangxi Ruiyu Construction Technology Co.,Ltd.,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]广西大学特色金属材料与组合结构全寿命安全国家重点实验室,南宁530004 [3]广西瑞宇建筑科技有限公司,南宁530004

出　　处：《上海交通大学学报》2025年第1期60-69,共10页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金(52068004)资助项目。

摘　　要：水平动荷载H(t)与扭矩T联合作用下的桩基受力变形较为复杂.为了更加准确地分析H(t)-T联合受荷桩的内力与位移,基于Pasternak地基模型考虑桩侧土体剪切效应;引入H(t)-T耦合因子,揭示多向荷载对桩身响应的影响机理;继而利用虚功原理推导桩身单元综合刚度矩阵;最后采用改进的有限杆单元法获得H(t)-T联合受荷桩内力与位移数值解;并与已有理论解和有限元模拟结果进行对比验证.参数分析表明:土体剪切效应可约束桩身水平位移,但对扭转变形影响较小;水平动荷载增强了桩身抗扭承载力,水平动荷载幅值从0.2Q_(u)增大到1.0Q_(u)时,桩顶扭转角减小了22.6%;增大动荷载无量纲频率会减小桩顶位移和桩身最大弯矩,外荷载动力效应随桩埋深增加而减弱;杆单元模型减少了单元划分数量和计算时间,可有效提高计算效率.The force and deformation of the pile foundation under the combined action of horizontal dynamic load H(t)and torque T are rather complicated.In order to more accurately analyze the internal force and displacement of the H(t)-T combined loaded piles,the shear effect of soil on the pile side is considered based on the Pasternak foundation model,and the H(t)-T coupling factor is introduced to reveal the influence mechanism of multi-directional load on pile response.Then,the virtual work principle is used to derive the comprehensive stiffness matrix of the pile element,and the modified finite beam element method is used to obtain the numerical solution of the internal force and displacement of the H(t)-T combined loaded piles.The results are compared with the results of the existing theoretical solutions and finite element simulation.The parametric analysis shows that soil shear effect can restrain the horizontal displacement of the pile,but has less effect on torsional deformation.The horizontal dynamic load enhances the torsional bearing capacity of the pile,and the torsional angle of the pile top is reduced by 22.6%when the horizontal dynamic load amplitude increases from 0.2 Q_(u) to 1.0 Q_(u).Increasing the dimensionless frequency of the dynamic load will reduce the displacement of pile top and the maximum bending moment of pile body.The dynamic effect of simple harmonic load will be weakened with the increase of pile burial depth.The beam element model significantly reduces the number of discrete units and computation time,which can effectively improve the computational efficiency.

关 键 词：Pasternak地基模型 联合受荷桩 有限单元法 水平动荷载 扭矩 

分 类 号：TU473.1[建筑科学—结构工程]