高密度电法在水库大坝渗漏勘察中的应用

Application of Electrical Resistivity Imaging to Reservoir Dam Leakage Investigation

运用高密度电法对某水库大坝进行渗漏探测,建立渗漏通道地电模型,通过单极-单极、偶极-偶极、温纳、温施等装置进行正演模拟,在分析4种装置模拟探测效果的基础上,采用温纳装置施工作业。介绍了高密度电法探测某水库大坝渗漏通道的具体情况,在正演模拟结果的基础上,对反演结果进行指导性解译,发现若干低阻异常区。在低阻异常区布设钻孔,并在钻孔中分段开展注水试验,验证了高密度电法对低阻异常区的研判结果。三维栅栏图直观反映了工区渗漏通道的空间发育规律。高密度电法在探测大坝渗漏通道中具有良好的效果。

Applying electrical resistivity imaging to detect the leakage of a reservoir dam,establishing the geoelectric model of leakage channel,forward modeling by Pole-Pole,Dipole-Dipole,Wenner Alpha and Wenner-Schlumberger,on the basis of analyzing the simulation results of four kinds of devices,this paper used the Wenner Alpha to construct the homework. This case described the specific conditions of electrical resistivity imaging detection of a reservoir dam leakage channel,interpreting of the inversion results on the basis of the forward simulation results and a number of low resistivity anomalies had been found. The sectional water injection test was done in holes which were in the low resistance resistivity anomalous area,verifying the results of the electrical resistivity imaging on low resistivity zone. The three-dimensional map directly reflected the spatial development rules of leakage channel,providing a reliable basis for late anti-seepage treatment. It shows that the electrical resistivity imaging has a good effect in detecting the seepage channel of the dam.