气泡轻质土空气耦合冲击回波响应特性研究  

Air Coupled Impact Echo Response Characteristics of Foamed Lightweight Soil

作　　者：张振[1,2] 张永刚 叶观宝[1,2] 刘洪伟 ZHANG Zhen;ZHANG Yonggang;YE Guanbao;LIU Hongwei(Department of Geotechnical Engineering College of Civil Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程学院地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《施工技术（中英文）》2023年第8期141-145,共5页Construction Technology

基　　金：国家自然科学基金青年项目(51508408);国家自然科学基金面上项目(41772281)。

摘　　要：实际工程中,气泡轻质土施工质量检测主要以钻孔取芯为主,该检测方法存在检测效率低、无法全面检测等不足,且对填筑体具有破坏性。开展气泡轻质土空气耦合冲击回波试验,获得不同密度气泡轻质土泄露波峰值频率;通过气泡轻质土泄露波与弯曲元测试的试样固有频率对比分析,揭示了气泡轻质土空气耦合冲击回波响应特性。通过空气耦合冲击回波试验发现,密度为0.5,0.8,1.2,1.5g/cm3气泡轻质土实测峰值频率平均值分别为654.77,872.66,1114.00,1505.94Hz,计算峰值频率与实测峰值频率相对误差基本在6%以内,验证了利用空气耦合冲击回波法检测不同密度气泡轻质土可行。并且,利用直径为10~20mm钢球敲击不同密度无缺陷气泡轻质土时,均能激发对应深度和密度下冲击回波模态,得到与计算频率较接近的实测频率。Coring method is mainly used for construction quality inspection of foamed lightweight soil in practice.This method is inefficient,unable to evaluate the construction quality comprehensively,and moreover it is destructive to the filling mass.A study on the air coupled impact echo test of foamed lightweight soil was conducted.The peak frequencies of the leaky wave of foamed lightweight soil samples with different densities were tested.In addition,bending element test was conducted to obtain the natural frequencies of the samples.Through a comparison and analysis of the samples’peak frequencies of leaky wave and the natural frequencies,the air coupled impact echo response characteristics of the foamed lightweight soil was revealed.It is found that the average measured peak frequency of foamed lightweight soill with the density of 0.5,0.8,1.2,1.5g/cm3 are 654.77,872.66,1114.00,1505.94Hz respectively through the air coupled impact echo test,and the relative error between the calculated peak frequency and the measured peak frequency is basically within 6%,which verifies that the air coupled impact echo method is feasible to detect foamed lightweight soil with different densities.Moreover,when using steel balls with 10~20mm diameters to knock flawless foamed lightweight soil of different densities,the impact echo modes at corresponding depths and densities can be excited,resulting in measured frequencies that are closer to the calculated frequencies.

关 键 词：气泡轻质土 空气耦合冲击回波法 泄露波 无损检测 频率 

分 类 号：TU521.3[建筑科学—建筑技术科学]