为了准确定位坝体渗漏位置,在直流电法的基础上,提出利用激励电压导通瞬间电极激发的瞬变电磁信号检测渗漏的方法。导通瞬间电极在导电介质中激发的瞬变电磁响应包含介质电导率信息,响应信号对水层等高阻介质比较敏感,响应变化较大,这是一种新的渗漏信息。利用该信息对坝体进行渗漏检测有助于提高渗漏点位置判断的准确性。利用电极检测系统对故县大坝进行实测,分别实现信号的廊道发射-水中接收和水中发射-廊道台阶接收,在横向和纵向判断了渗漏异常位置。对故县大坝的实测数据进行分析,结果表明在大坝的2^#—3^#横缝处存在渗漏,与实际渗漏情况相符。研究成果对于准确定位坝体渗漏位置有一定的参考价值。

Ensuring engineering safety is of utmost importance during the construction and maintenance of dams. Regular leakage inspections play a critical role in preventing potential engineering disasters. To precisely locate dam body leaks, we propose a transient electromagnetic detection method utilizing electrode excitation. The electrodes generate transient electromagnetic fields in the conducting medium at the moment of power supply, while the resulting response signal carries conductivity information of the medium. Leakage within the dam body induces changes in medium conductivity, consequently impacting the transient electromagnetic response. Notably, in high-resistance media like aquifers, the response signal propagates faster and exhibits larger signal values, which is conducive to improving the accuracy of identifying leakage point. Employing the electrode system, we implemented three detection schemes to measure leaks in the Guxian dam. By performing corridor-based transmission and underwater-based reception, as well as underwater transmission with reception at corridor steps, we identified the leakage position from both horizontal and vertical perspectives. Analysis of the measured data confirmed leakage at the transverse joints between the 2^# and 3^# sections, aligning with the actual situation.