水平激振下饱和土中楔形桩动力阻抗分析  

Dynamic Impedence Analysis of Tapered Pile in Saturated Soil under Horizontal Vibration

作　　者：胡安峰[1] 陈正[1] 肖志荣 谢森林 陈奕扬 HU Anfeng;CHEN Zheng;XIAO Zhirong;XIE Senlin;CHEN Yiyang(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;School of Civil Engineering and Architecture,Zhejiang University of Science and Technology,Hangzhou 310023,China)

机构地区：[1]浙江大学滨海和城市岩土工程研究中心,浙江杭州310058 [2]浙江科技学院土木与建筑工程学院,浙江杭州310023

出　　处：《湖南大学学报（自然科学版）》2023年第5期181-190,共10页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51978612,51778572)。

摘　　要：基于Biot饱和多孔介质理论,将桩体简化为Euler梁,建立水平稳态激振下楔形桩-土耦合振动模型.首先通过引入势函数,求解平面应变条件下桩周土振动控制方程,并利用分离变量法和算子分解法求得各桩段土反力.再结合桩土耦合及位移连续条件,求解得到楔形桩桩顶阻抗解析解.通过算例分析,研究了楔角、长径比以及土体渗透性等因素对楔形桩桩顶阻抗的影响.结果表明:1)在低频范围内,楔形桩阻抗会随楔角增大而减小;2)桩底尺寸一致时,桩顶水平阻抗、摇摆阻抗随长径比的增大而增大;3)对于桩长相同、楔角不同的等体积楔形桩,在低频阶段水平动刚度随楔角增大而减小,而高频阶段则相反;4)土中液相的存在对桩顶动力阻抗有显著影响,忽略土中液相作用会低估桩顶动力阻抗;5)表层软土会降低楔形桩桩底动阻抗.Based on the theory of Bio-saturated porous media,the tapered pile was simplified into an Euler beam,and a tapered pile-soil coupling model under the horizontal steady-state vibration was established.Firstly,the potential function is introduced to solve the vibration control equation of soil around each pile section under the plane strain model.The earth pressure around the pile section of each layer is obtained by using variable separation methods and operator decomposition methods.Combining the conditions of pile-soil coupling and displacement conti⁃nuity,the impedance solution of tapered pile top is obtained.The effects of wedge angle,length diameter ratio,and soil permeability on the top impedance of a wedge-shaped pile are studied based on the analysis of examples.The re⁃sults show that:1)in the low-frequency range,the impedance of the tapered pile decreases with the increase of wedge angle;2)increasing the length of the tapered pile can improve the horizontal impedance and rocking imped⁃ance of the pile head;3)keeping the volume and length of pile unchanged,the horizontal dynamic stiffness decreases with the increase of wedge angle in low-frequency stage,but the result is opposite in high-frequency stage;4)the existence of liquid phase in soil has a significant effect on the dynamic impedance of pile top,and neglecting the action of the liquid phase in the soil leads to underestimating the dynamic impedance of tapered pile;5)surface soft soil reduces the dynamic impendence of the tapered pile.

关 键 词：振动分析 动力响应 饱和土 楔形桩 

分 类 号：TU473.1[建筑科学—结构工程]