GPR技术在南水北调工程坝体渗漏探测中的应用

坝体渗漏严重威胁着堤坝结构安全。针对探地雷达(GPR)技术在堤坝结构安全探测中存在的因电磁波衰减造成探测深度浅、精度低的问题,提出了一种天线中心频率为50 MHz增强型低频组合天线技术,通过双发双收设计提高天线的发射效率并增强GPR深部探测能力。应用该技术进行的南水北调工程坝体渗漏探测试验,结果表明:与常规雷达天线相比,该增强型低频组合天线可有效增强深部探测能力,在含水量较大的坝体环境下有效探测深度达到25 m,实现了富水区域及渗流通道的探测。本技术为堤坝安全治理提供了数据支撑。

Application of GPR Technology to Dam Leakage Detection in the South-to-North Water Transfer Project

Dam leakage is a serious threat to the structural safety of dam. GPR (Ground Penetrating Radar) technology has such shortcomings as low depth of detection and low precision caused by electromagnetic wave attenuation in the safety detection of dam structure. In view of this, we propose a combined antenna technology with enhanced low frequency and antenna center frequency at 50 MHz. Dual-transmitter and dual-receiver design is employed to improve the antenna’s emission efficiency and enhance the capability of GPR’s deep detection. We further apply this technology to the leakage detection experiments for the dam of the South-North Water Transfer Project. Results demonstrate that compared with conventional radar antenna, the proposed enhanced low-frequency antenna effectively enhances the deep detection capability and effectively detect the abnormal target within 25 m depth in large moisture content environment, thus achieving the detection of water-rich areas and leakage channel. This technology provides data support for the safe management of dams.