基于高密度电法的土石坝渗漏探测

为消除高密度电法渗漏探测时存在的体积效应,准确探明土石坝渗漏位置,文章通过室内试验建立了坝体填筑土电阻率与含水率相关关系,并将其用于解译高密度电法探测结果。结果表明,随含水率增大,电阻率逐渐减小,电阻率与含水率存在明显的幂函数相关关系,当含水率大于30%时,随含水率增大,土体电阻率保持不变;坝体表面和6m深度以下存在低阻异常,经分析坝体表面低阻异常原因为大气降雨等环境因素影响导致其含水率偏高,而6m深度以下坝体低阻异常原因为坝体渗漏;建立的坝体填筑土电阻率与含水率相关关系,可明显提高高密度电法解译精度,更加准确地判断土石坝渗漏情况。

Detection of Earth-rock Dam Leakage based on High-density Electrical Method

The correlation between the resistivity of dam filling soil and water content is established through laboratory tests in the paper in order to eliminate the volume effect during leakage detection by the high-density electrical method,and accurately identify the leakage location of the earth-rock dam,and it is used for interpreting the detection results of the high-density electrical method.The results show that the resistivity decreases gradually with the increase of water content,and there is an obvious power function correlation between resistivity and water content.When the water content is greater than 30%,the resistivity of soil mass remains unchanged with the increase of water content.There are low resistivity anomalies on the dam surface and area below 6m depth.The reason for low resistivity anomalies on the dam surface is the high water content caused by atmospheric rainfall and other environmental factors after analysis,while dam leakage is the reason for low resistivity anomalies on the dam body in the area below 6m depth.The correlation between filling soil resistivity and water content of the established dam can improve the interpretation accuracy of the high-density electrical method and judge the leakage of earth-rock dam more accurately.