Study on the Effect of Low-Temperature Anode Filled with FeCl3 Solution on Electro-Osmotic Reinforcement of Soft Clay

Abstract

In order to study the effect of FeCl3 solution on the current, soil pH value, drainage volume, anode potential difference, energy consumption, and resistivity of electro-osmosis consolidation of soft clay with different moisture contents under a low temperature environment, we carried out 31 sets of model tests under different working conditions by using a self-made device and an improved Miller Soil Box. The test results showed that, under the same conditions, although the energy consumption coefficient of electro-osmosis had little change in the low temperature environment, the current, displacement, and electro-osmosis coefficient were obviously reduced, and the resistivity and anode potential difference was greatly increased, indicating that the low temperature environment reduces the efficiency of electro-osmosis of soft clay. After the anode was filled with FeCl3 solution, the current, water displacement, and electro-osmotic coefficient were clearly increased; the anode potential difference and electro-osmotic energy consumption coefficient were clearly decreased; and the resistivity was reduced to a certain extent, which indicates that the anode filled with FeCl3 solution is very beneficial in improving electro-osmotic efficiency and in saving energy. The electro-osmotic discharge after the anode filled with FeCl3 solution at low temperature was clearly higher than that after the anode was filled water at normal temperature, indicating that the effect of the anode filled with FeCl3 solution on electro-osmosis is greater than that of temperature. In the process of electro-osmosis of soft clay, the better the electro-osmosis effect, the smaller the pH value of the anode and the larger the pH value of the cathode. The pH value of the cathode and anode can be used as one of the indexes to reflect the electro-osmosis effect.