Detection of the Embankment Slope Formed by the Mixed Fill of Coal and Soil by GPR

[Purpose] The slope formed by the mixed fill of coal and soil is prone to disease problems such as unconsolidated and hollowness because of particle loss. High-frequency GPR can easily detect the relevant diseases near the surface and make targeted treatments. [Methods] Based on the theoretical study of the propagation mechanism of GPR electromagnetic waves in multiple geological layers and the numerical method of the FDTD method, the layered geoelectrical model of the high embankment system is established. Reflection amplitude and electric field intensity of GPR wave in multilayer embankment are deduced. [Results] The change of electrical parameters in the stratum inevitably causes the change of echo characteristics. With the increase of relative permittivity in the stratum, the amplitude of GPR echoes increases significantly. While the amplitude of echoes does not increase significantly with the increase of conductivity in the stratum in a certain range. [Conclusion] The above conclusions make an important guiding significance for the detection of the slope formed by the mixed fill of coal and soil.