Method for detecting dam seepage through combination of surface nuclear magnetic resonance method and high-density resistivity method

Abstract

The invention discloses a method for detecting dam seepage through combination of a surface nuclear magnetic resonance method and a high-density resistivity method Firstly, a suspected resistivity abnormal area is quickly analyzed and determined through the high-density resistivity method. Then key detection and abnormal region identification are performed on the suspected resistivity abnormal area through the surface nuclear magnetic resonance method. Finally a dam seepage channel is determined through integrating the detecting results of the surface nuclear magnetic resonance method and thehigh-density resistivity method, thereby diagnosing and determining a seepage hidden trouble range and a degree. According to the method, the number of coil turns can be set for aiming at different conditions for improving a signal-to-noise ratio, thereby reducing interference to a surface nuclear magnetic resonance method detecting signal, and remarkably improving precision of detecting information. Furthermore, the surface nuclear magnetic resonance method and the high-density resistivity method have low comprehensive detecting cost and can verify each other, thereby supplying a new approachfor settling a problem of non-uniqueness in interpreting a resistivity method detecting accomplishment.

Description

technical field [0001] The invention relates to the field of geophysical detection of water conservancy projects, in particular to a method for detecting hidden dangers of dam leakage based on high-density electrical method and nuclear magnetic resonance technology. Background technique [0002] When there are hidden dangers or leakage in the earth-rock dam, among all the physical parameters that can be used for detection, the resistivity response of the soil medium is the most sensitive and easy to detect non-destructively, so the electrical method has become the most common method for detecting the hidden danger of earth-rock dam leakage . At present, there are more than 20 kinds of electrical methods actually applied in the field of geological and geophysical prospecting. These methods detect the resistivity of the earth dam body medium, interpret the abnormal area characteristics of the detection results map, and then infer whether there are hidden dangers. It is an ind...

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Problems solved by technology

[0005] Although the MRS method has the advantages of directly detecting seepage water and distinguishing anomalies in low-resistivity areas of rock formations, and can quantitatively obtain various parameters such as stratified water content, porosity, and permeability coefficient, but after Tian Baofeng et al. According to the research in the article "A Method for Suppressing Magnetic Resonance Signal Noise Adaptive with Variable Step Size", it is found that due to the limitation of the detection principle, when this method is used for detection, it is easily affected by the surrounding electromagnetic field environment, noise and other environments, and its 2D / 3D imaging The technology is still in the research and exploration stage, and the information resolution of the obtained one-dimensional results is insufficient, so it is difficult to accurately judge the leakage location by using it alone

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