扩径缺陷对桩基低应变反射波影响的数值模拟分析  

Numerical Simulation Analysis of the Effect of Diameter Expansion Defects on Low-strain Reflection Waves in Pile Foundations

作　　者：冉芸诚 李东晋 余颜江 RAN Yuncheng;LI Dongjin;YU Yanjiang(China Merchants Chongqing Highway Engineering Testing Center Co.,Ltd.,Chongqing 400067)

机构地区：[1]招商局重庆公路工程检测中心有限公司,重庆400067

出　　处：《公路交通技术》2024年第6期81-89,共9页Technology of Highway and Transport

基　　金：重庆市交通科技自筹项目(CQJT2022ZC04)。

摘　　要：低应变反射波法因其高效且经济的优势,被广泛用于基桩完整性检测。为研究扩径缺陷对桩基低应变反射波形的影响,运用有限元软件ABAQUS,采用Explicit分析模块,分别研究了扩径面积和扩径厚度对桩基低应变反射曲线影响的规律。结果表明:1)采用ABAQUS/Explicit分析模块能较好地模拟桩基低应变反射曲线;2)在其他参数一定时,随着扩径面积或扩径厚度的增大,扩径处反射子波幅值逐渐增大,桩底反射子波逐渐减小;3)扩径厚度越大,扩径特征反射波出现与消失之间的时差越来越大;4)桩基现场检测仅能根据幅值波动趋势定性判别缺陷的严重与否,尚不能定量判断扩径的面积或厚度。The low strain reflection wave method is widely used for pile integrity testing due to its high efficiency and economic advantages.To investigate the influence of expansion defects on the low strain reflection waveform of pile foundations,the finite element software ABAQUS was used,and the Explicit analysis module was employed to study the laws of the influence of expansion area and expansion thickness on the low strain reflection curve of pile foundations.The results show that:1)Using ABAQUS/explicit analysis module can simulate the low strain reflection curve of pile foundation well;2)When other parameters are constant,as the expansion area or thickness increases,the amplitude of the reflected wave at the expansion site gradually increases,and the reflected wave at the bottom of the pile gradually decreases;3)The larger the thickness of the expansion,the greater the time difference between the appearance and disappearance of the characteristic reflected waves of the expansion;4)On site inspection of pile foundations can only qualitatively determine the severity of defects based on amplitude fluctuation trends,and cannot yet quantitatively determine the area or thickness of diameter expansion.

关 键 词：低应变法检测 桩基扩径缺陷 三维桩-土有限元模型 数值模拟 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]