黏弹性土中异形桩横向动力响应半解析解  

Semi-analytical solution for lateral dynamic response of non-circular piles in viscoelastic soil

作　　者：周航[1,2] 汪义圣 亓戈平 ZHOU Hang;WANG YI-sheng;QI GE-ping(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400450 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400450

出　　处：《岩土力学》2025年第3期761-774,共14页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.52278330,No.52027812);重庆市科技创新重大研发项目(No.CSTB2023TIAD-STX0042);国家重点研发计划(No.2022YFB2601903)。

摘　　要：横截面异形桩是一种截面非圆的桩型,因其复杂的边界条件,使得受力特性不同于圆桩,目前关于异形桩横向动力响应的理论分析方法较为缺乏。为了研究异形桩在均质黏弹性土中的横向动力响应,将土体视为近似连续介质,基于变分原理和哈密顿原理导出直角坐标系下的桩-土体系控制方程。运用COMSOL物理场中的偏微分方程接口求解含复杂边界条件的土体位移函数,用Matlab中的BVP4c函数求解桩身位移函数,在Matlab中编写迭代程序可得桩身位移函数和土体位移函数的半解析解。将结果与现有圆桩理论解进行对比,结果吻合效果较好。对异形桩进行分析发现,横截面积相等时,形状对桩顶动力响应影响明显,H形桩的桩顶阻抗最大;横截面惯性矩相等时,X形桩的桩顶阻抗最大。以X形桩为例,桩顶阻抗随桩-土模量比的增大而增大;共振频率及桩顶阻尼随长径比的增大而减小,桩顶刚度随长径比增大而增大。Piles with non-circular cross-sections are characterized by their non-circular shapes.Due to their complex boundary conditions,their mechanical behavior differs from that of circular piles.Currently,there is a lack of theoretical analysis methods for the lateral dynamic response of such piles.In order to investigate the lateral dynamic response of these piles in homogeneous viscoelastic soil,the soil is approximated as a continuous medium,and the governing equations of the pile-soil system in Cartesian coordinates are derived based on the variational principle and Hamilton’s principle.The displacement function of the soil,considering complex boundary conditions,is solved using the partial differential equation(PDE)interface in COMSOL Multiphysics,while the displacement function of the pile is solved using the BVP4c function in Matlab.An iterative procedure is implemented in Matlab to obtain semi-analytical solutions for both the pile and soil displacement functions.The obtained results are compared with existing theoretical solutions for circular piles,showing good agreement.Analysis of the irregular-shaped piles reveals that,when the cross-sectional area is constant,the shape significantly affects the dynamic response at the pile head,with H-shaped piles exhibiting the highest impedance.When the cross-sectional moment of inertia is constant,X-shaped piles show the highest impedance.Taking X-shaped piles as an example,the impedance at the pile head increases with the pile-soil modulus ratio.As the length-to-diameter ratio increases,the resonance frequency and damping at the pile head decrease,while the stiffness at the pile head increases.

关 键 词：异形桩 黏弹性土 半解析解 横向动力荷载 桩顶阻抗 

分 类 号：TU441[建筑科学—岩土工程]