Experimental And Numerical Simulation Research On Electric Shock Characteristics Of Hydraulic Fill

In general, lightning always occur in the ground where has a lower or unequally distributed soil resistivity. Guangxi is located in the thunderstorms active area. In recent years, a large number of artificial land have been formed under the influence of sea reclamation project. Therefore, the foundation soil tend to have the following characteristics, high water content, high clay content, high void ratio, low and unequally distributed resistivity, what would bring some hidden troubles for lightning protection in this region. At present, the researchs on interaction between electric field and soil mainly included the basic electrical theory and application of soil and its influence in the electrical engineering. Therefore, there is of great theoretical significance and engineering significance to carry out the electrical response regularity of hydraulic fill and corresponding experimental study on electric shock characteristics under the effect of lightning electric field.By taking the hydraulic fill collected from Guangxi Beibu Gulf Economic Zone as the research object, and combining with theoretical analysis, a experimental study on electric shock characteristics of hydraulic fill with different physical properties has been carried out, and the electrical response regularity has been studied base on numerical simulation under the effect of lightning electric field in this article. The main achievements and results are as follows:(1) Base on the soil conductivity theory and the electric breakdown theory, electrical property and breakdown characteristics are mostly depended on pore water and structural of hydraulic fill. According to this result, an electric shock model suitable for hydraulic fill was established.(2) By using the impulse voltage generator,we carried out a electric shock characteristic test on hydraulic fill with different water content, dry density and salt content. The experimental results showed that breakdown strength of hydraulic fill has a logarithmic relationship decreasing with the water content and dry density, and a exponential relationship decreasing with salt content. When the water content increased from15%to27%, the breakdown voltage decrease from8.23kV/cm to6.57kV/cm, the proportion of decrease is20.2%. When the dry density increased from1.4g/cm3to1.7g/cm3, the breakdown voltage decrease from8.03kV/cm to7.10kV/cm, the proportion of decrease is11.2%. When NaCl content increased from0%to2.0%, the breakdown voltage decrease from8.11kV/cm to6.86kV/cm, the proportion of decrease is15.4%.(3) According to the electrical shock model of hydraulic fill, the spatial distribution and time-varying characteristics of internal electric field in soil under the action of the impulse voltage have been researched by using COMSOL Multiphysics numerical simulation software. The results show that the maximum electric field strength of soil would reach a larger value(7.282kV/cm) when the water content, dry density and salt content of soil are lower, and weaken to4.464kV/cm while they are higher.(4) Compared with the electric shock characteristic test and numerical simulation results, it is show that hydraulic fill with a higher water content, dry density and salt content would be influenced more significantly and rapidly under the impulse electric field.