基于点电偶源的土石堤坝管涌渗漏通道探测方法与仪器设计

Detection method and instrument design for piping paths in earth-rock dams based on electric dipole sources

土石坝是一种常见的水利工程结构,土石材料的结构特性决定着渗漏的必然性,异常的渗漏可能导致坝体内部土的壤受到侵蚀,逐渐地形成了管涌渗漏通道.如果不采取有效措施提前探测和治理管涌渗漏通道,坝体可能面临沉降、滑坡或坍塌等风险.为了能够准确地探测土石坝管涌渗漏通道的位置,为堤坝治理提供更丰富的探测数据,本文基于管涌渗漏通道的电导率异常分布特性,研制出一种渗漏探测仪器.该仪器包含发射系统和接收系统.发射系统用于激励管涌渗漏通道产生异常磁场;接收系统由三分量磁测传感器、Real-Time Kinematic(RTK)定位系统和接收机组成,用于测量和记录微弱的异常磁场信号的幅度和厘米级经纬度信息.通过仿真、实验室测试以及野外实验,验证了探测方法和仪器的有效性.该技术和仪器有望在堤坝安全性监测和维护方面发挥重要作用,为减少土石坝潜在的灾害提供了一种先进的探测技术手段.

Earth-rockfill dams are common hydraulic engineering structures,where the structural characteristics of soil and rock materials inherently lead to seepage.Abnormal seepage can result in the erosion of internal soil,gradually forming piping leakage channels.If effective measures are not taken to detect and manage these piping leakage channels in advance,the dam may face risks such as settlement,landslides,or collapse.To accurately locate the position of piping leakage channels and provide richer detection data for dam management,this paper develops a leakage detection instrument based on the abnormal distribution characteristics of electrical conductivity associated with these channels.The instrument consists of a transmission system and a reception system.The transmission system is designed to induce an abnormal magnetic field in the piping leakage channels,while the reception system comprises a three-component magnetometer,a Real-Time Kinematic(RTK)positioning system,and a receiver to measure and record the amplitude of weak abnormal magnetic signals along with centimeter-level latitude and longitude information.Through simulations,laboratory tests,and field experiments,the effectiveness of the detection method and instrument has been successfully validated.This instrument and method are expected to play a crucial role in monitoring and maintaining dam safety,providing an advanced detection technology to mitigate potential disasters associated with earth-rockfill dams.