堤坝渗漏感应磁梯度检测可行性研究
Dam Leakage Sensing Magnetic Gradient Detection Feasibility Study

堤坝的渗漏检测对堤坝的安全运行有着重要的意义。由于磁梯度测量具有观测无需与地面接触、野外容易操作以及受地磁场影响较小等优点，该技术可以很好的应用于堤坝渗漏检测当中。为了研究磁梯度张量与渗漏通道之间的关系，本文从频率域Maxwell方程组出发推导控制方程，利用有限元实现了三维频率域磁场正演，并通过理论模型测试了算法的正确性。利用高阶紧致差分算法实现了磁梯度张量的高精度计算。接着文章分析了不同模型参数磁梯度张量和渗漏通道之间的关系，表明Byz和Bzz分量可以很好的反映渗漏通道的位置。通过对磁梯度的求解避免了理论计算磁场所带来的误差，并且提高了异常分辨率。通过本文的研究，可以为实际工作中的参数设计提供理论指导。
The leakage detection of dam is of great significance for the safe operation. Because the magnetic gradient measurement has the advantages of no need to contact the ground, it is easy to operate, and it is less affected by the ground magnetic field when observing. This technology can be well applied in the leak detection. In order to study the relationship between the magnetic gradient and the leakage, this article derives the control equation from the frequency domain Maxwell equation, uses the finite element to achieve the 3D frequency domain magnetic field forward, and tests the correctness of the algorithm through the theoretical model. High-order compact difference scheme is used to achieve the high-precision calculation of magnetic gradient tensor. Then this article analyzes the relationship between the gradient tensor and the leakage channel of different model parameters. It shows that Byz and Bzz can reflect the position of the leakage channel. The solution to the magnetic gradient avoids the error caused by the theoretical calculation of the magnetic place, and improves abnormal resolution. Through the research of this article, the theoretical guidance can be provided for parameter design in actual work.