探地雷达和高密度电法识别大坝塑性混凝土防渗墙渗漏缺陷研究  

Research on Identifying Leakage Defects of Plastic Concrete Cutoff Walls in Dams by Ground Penetrating Radar and High Density Electrical Method

作　　者：姚纪华 伍佑伦 宋子龙 刘亚玲 梁经纬 王祥 Yao Jihua;Wu Youlun;Song Zilong;Liu Yaling;Liang Jingwei;Wang Xiang(Hunan Water Resources and Hydropower Research Institute,Changsha Hunan 410007,China;Hunan Province Dam Safety and Disease Prevention Engineering Technology Research Center,Changsha Hunan 410007,China;Hunan Jiuyi Engineering Design Co.,Ltd,Changsha Hunan 424100,China)

机构地区：[1]湖南省水利水电科学研究院,湖南长沙410007 [2]湖南省大坝安全与病害防治工程技术研究中心,湖南长沙410007 [3]湖南九一工程设计有限公司,湖南长沙424100

出　　处：《工程地球物理学报》2023年第5期599-604,共6页Chinese Journal of Engineering Geophysics

基　　金：长沙市自然科学基金(编号:kq2202358);湖南省重大水利科技项目(编号:XSKJ2021000-09);湖南省水利水电科学研究院优秀人才培养支撑项目(编号:2021-11)。

摘　　要：某水库大坝下游坝坡存在滑坡、散浸和集中渗漏,为了揭露出仅60 cm厚塑性混凝土防渗墙的渗漏缺陷,实现高效防渗补漏,本文综合采用高密度电阻率法、探地雷达法对塑性混凝土防渗墙的渗漏缺陷进行识别。经过两种物探法二维反演影像图比对印证,获得渗漏缺陷二维空间位置及规模,针对性地对其进行灌浆补强,大坝下游坝坡散浸区及集中渗漏点消失,险情得以有效解决。结果表明:综合高密度电阻率法、探地雷达法能较准确地解译出大坝塑性混凝土防渗墙渗漏缺陷区域位置及规模,相比单一物探法,误差率减少30%左右;大坝塑性混凝土防渗墙存在4个渗漏缺陷区,皆集中于坝顶以下深度9~23 m范围,结构质量较差;补强区防渗墙体的视电阻率得到极大提高,但相比原无缺陷区,依然偏低,其结构质量、密实度、抗渗透破坏性能和抗溶蚀衰减性能可能将弱于原无缺陷区。Landslides,scattered seepage,and concentrated leakage often occur on the downstream slope of a certain reservoir dam.In order to reveal the leakage defects of a plastic concrete anti-seepage wall with a thickness of only 60 cm and achieve efficient anti-seepage and leakage repair,this paper comprehensively uses high-density resistivity method and ground penetrating radar method to identify leakage defects of plastic concrete anti-seepage walls.After comparing and verifying the two-dimensional inversion images of two geophysical methods,the two-dimensional spatial location and scale of leakage defects were obtained.Targeted grouting reinforcement was carried out to eliminate the scattered seepage area and concentrated leakage points on the downstream dam slope,effectively solving the danger situation.The results show that:The comprehensive high-density resistivity method and ground penetrating radar method can accurately interpret the location and scale of leakage defects in the plastic concrete anti-seepage wall of the dam,which reduces the error rate by about 30% than a single geophysical method;Four leakage defect areas are detected in the plastic concrete anti-seepage wall of the dam,all concentrated in the depth range of 9~23 m below the dam crest,with poor structural quality;The apparent resistivity of the anti-seepage wall in the reinforcement area has been greatly improved,but it is still relatively low compared with the original defect free area.Its structural quality,compactness,permeability failure resistance,and corrosion attenuation resistance may be weaker than the original defect free area.

关 键 词：大坝塑性混凝土防渗墙 渗漏缺陷 高密度电阻率法 探地雷达法 

分 类 号：P631.3[天文地球—地质矿产勘探]