Abstract: Seepage piping is a most common failure mode of dike. Accurate detection of dike piping channels during high water level is of great significance to the reinforcement of dike. We propose a method to identify seepage channel by providing artificial current to the seepage opening and observing the primary induced weak magnetic field energy generated by the conductive circuit of the seepage channel. Based on laboratory physical parameter test and forward simulation calculation, we looked into the variation trend of electrical conductivity of embankment soil with water content, and revealed the spatial distribution characteristics of weak magnetic field in different seepage channels. We further summarized the variation law of weak magnetic field intensity and current density with the depth and conductivity of leakage channel. The results of physical model test show that the weak magnetic detection method effectively identifies the spatial distribution of seepage channels. It is highly efficient and has strong anti-interference capability with no grounding electrode. It is expected to offer pragmatic value for promoting the detection technology of hidden seepage danger in dike.

Key words: hidden danger of dike, seepage channel, weak magnetic detection technology, weak magnetic field characteristics, primary induced magnetic field