冲击回波法检测钢衬混凝土组合结构脱空缺陷试验研究与应用  

Experimental research and application on the detection of contact surface cavity defects in steel-lined concrete composite structure by impact echo method

作　　者：李军[1,2] 刘文昊[1] 杨建喜 贾海磊 沙迎春 LI Jun;LIU Wenhao;YANG Jianxi;JIA Hailei;SHA Yingchun(Nanjing Hydraulic Research Institute,State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing 210029,Jiangsu,China;Hohai University,Nanjing 210098,Jiangsu,China;Guangdong Yuehai Pearl River Delta Water Supply Co.,Ltd.,Guangzhou 511458,Guangdong,China)

机构地区：[1]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,江苏南京210029 [2]河海大学,江苏南京210024 [3]广东粤海珠三角供水有限公司,广东广州511458

出　　处：《水利水电技术（中英文）》2023年第7期128-140,共13页Water Resources and Hydropower Engineering

基　　金：中央级公益性科研院所基本科研业务费专项资金资助(Y420014,Y420015);珠江三角洲水资源配置工程课题研究(CD88-GC02-2020-0034)。

摘　　要：【目的】采用钢衬混凝土组合结构的水工隧洞和压力管道在工程实际中常常只具备单一检测面,钢衬和混凝土之间的表面脱空质量缺陷如何检测属于无损检测技术难点。【方法】通过制作不同规格尺寸的钢衬混凝土脱空缺陷模拟体,采用以低频弹性波为媒介的冲击回波法开展模型试验研究,分析缺陷部位的反射P波首波到达时间、振幅和卓越频率等时域信号及频域信号识别参数,在此基础上提出频率幅值密度比作为定量检测表面脱空质量缺陷的识别参数。【结果】结果表明:脱空缺陷对P波信号影响范围为两倍脱空直径,从缺陷边缘到缺陷中心卓越频率保持最低值不变;脱空厚度对P波的绕射作用相较于脱空表面积更为明显;随着脱空缺陷体积的增加,反射P波首波振幅呈现逐渐降低的趋势,卓越频率逐渐减小。【结论】工程实践研究验证了检测识别参数的适用性,冲击回波法可以检测钢板衬砌混凝土叠合结构表面脱空质量缺陷,并能够初步确定缺陷位置、大小及形状。[Objective]In engineering practice,hydraulic tunnel and pressure piping with steel lined concrete composite structures often only have a single detection surface,how to detect the quality defects of contact surface cavity between steel lining and concrete is a technical difficulty of nondestructive testing.[Methods]The authors created different specifications and sizes simulations of steel lined concrete contact surface cavity defects,carried out model test research using the impact echo method with low-frequency elastic wave as the medium,analyzed the identification parameters of time-domain signals and frequency-domain signals such as the reception time,amplitude and predominant frequency of the first wave of reflected P wave at the defect location,and proposed the frequency amplitude density ratio as the identification parameter for quantitative detection of surface void quality defects.[Results]The test result show that the influence range of contact surface cavity defect on P wave signal is twice the cavity diameter,and the predominant frequency from the edge of the defect to the center of the defect remains the lowest value.The effect of cavity thickness on P wave diffraction is more obvious than that of cavity surface area.With the increase of cavity defect volume,the amplitude of reflected P wave head wave decreases gradually,and the predominant frequency decreases gradually.[Conclusion]The engineering practice research has verified the applicability of the detection and identification parameters.The impact echo method can detect the surface cavity quality defects of the steel lining concrete composite structure,and can preliminarily determine the defect location,size and shape.

关 键 词：钢衬混凝土 组合结构 表面脱空 冲击回波法 幅值密度比 

分 类 号：TV698[水利工程—水利水电工程]