摘要
GPR技术近年来在许多领域得到了广泛应用,但公路工程在道路脱空探测时对于充水型脱空无法检测,且从未在模袋护坡工程检测中应用。鉴于此,通过室内模型试验,研究了模袋含水率对波速和相对介电常数的影响,并分析了电磁波波长在模袋中的变化情况;通过水池模型试验,在不同电导率的水中对电磁波波速、波长、衰减常数和趋肤深度进行了研究分析。结果表明:模袋护坡工程探测时,应尽量选择高频天线,以提高钢筋分辨率,且重点考虑模袋含水率的影响,选取准确的相对介电常数,准确计算钢筋位置。充水型脱空探测时,应重点考虑水中电磁波的衰减,高频段衰减程度取决于水的电导率。当水的电导率不大于0.1 s/m时,高频段天线均可探测到脱空层底部;当水的电导率大于0.1 s/m和小于1 s/m时,高频段天线均识别困难;当电导率达到1 s/m时,高频段的所有频率均无法识别。
GPR technology has been widely used in many fields in recent years,but it can‘t detect water-filled cavitation in road release de⁃tection in highway engineering,and it has never been applied in the detection of bag slope protection project.In view of this,this paper stud⁃ied the influence of the moisture content of the bag on the wave velocity and the relative dielectric constant through laboratory model tests,and analyzed the changes of electromagnetic wave wavelength in the mold bags.The velocity,wavelength,attenuation constant and skin depth of electromagnetic wave in water with different conductivity were studied and analyzed by pool model test.The results show that in the detection of the mold bag slope protection project,high frequency antenna should be selected as far as possible to improve the resolution of steel bar,and the influence of water content of the bag should be mainly considered,and accurate relative dielectric constant should be se⁃lected to accurately calculate the position of steel bar.In water-filled cavitation detection,the attenuation of electromagnetic wave in water should be considered,and the attenuation degree of high frequency band depends on the conductivity of water.When the conductivity of wa⁃ter is less than 0.1 s/m,the bottom of the void layer can be detected by high frequency antenna.When the water conductivity is greater than 0.1 s/m and less than 1 s/m,it is difficult for high frequency antennas to recognize.When the conductivity reaches 1 s/m,all frequencies in the high band can′t be recognized.
作者
袁金峰
赵丽君
崔洪礼
张丽梅
鞠政
李健
YUAN Jin-feng;ZHAO Li-jun;CUI Hong-li;Zhang Li-mei;JU Zheng;LI Jian(Jilin Institute of Water Resources,Changchun 130022,Jilin Province,China;Key Laboratory of Automobile Materials,Ministry of Education and School of Materials Science and Engineering,Jilin University,Changchun 130022,Jilin Province,China)
出处
《中国农村水利水电》
北大核心
2024年第7期170-176,182,共8页
China Rural Water and Hydropower
基金
吉林省科技发展计划项目(20210203212SF)。
关键词
GPR技术
模袋脱空检测
相对介电常数
电导率
充水型脱空
GPR technology
bag emptying detection
relative dielectric constant
electrical conductivity
water-filled emptying
