The Mechanism Research On Electrical Response Of Dredger Fill In The External Electric Field

Compared with other soil types, dredger fill contains large amount of moisture and salt, has high void ratio and organic content. These properties reduce the soil’s electric resistivity to a great extent. Up till now, only a handful of researches on the electrical property of dredger fill, its response to added electric fields in terms of electric potential’s changes and electrons’ moving patterns are conducted. This dissertation studies dredger fill’s internal electrical response to added electric fields.This dissertation uses dredger fill samples acquired from the Beibu Bay Economic Zone as subject of research. Samples are first put through a series of tests to get a thorough analysis on the soil’s physical and chemical properties. These tests include consolidation test, tri-axial shear test, particle size analysis, penetration test, etc. Then a series of controlled experiments are run to study the electrical property of this soil type and its affecting factors. The result suggests a significant negative correlation between the resistivity of the soil and the soil’s moisture content, relative compactness, and salt content. The study was earried further by putting soil samples under electric fields to study the internal electrical response of this soil type. Findings thus acquired can be summarized as the following three points:(1) Without the impact of artificially added electric fields, dredger fill is still permanently under the impact of atmospheric electric field, and the soil’s internal electrical direction concurs with the atmospheric electric field’s direction.(2) The stronger the added electric field, the more the impact on the soil’s internal electric charge, and the quicker the accumulative changes of the electric potential difference between the two ends of the sample.(3) the probes at the two ends of the sample measuring electric potential difference acquire the quickest reading changes in samples having a25%moisture content ratio, reaching-868mV in about five days. Samples with a relative compactness of0.8manifests significant response in terms of internal electric charge change. Samples containing0.18%of salt can obtain a maximum change of-156mV in their electric potential difference in25days. The lower the salt content ratio, the weaker the impact of external electric fields on the soil’s internal electric charge.