Experimental Study On The Influence Of Different Electro-osmosis Conditions On The Characteristics Of Soft Clay

Electroosmosis is an effective method for consolidation treatment of soft soil,which is by inserting electrodes in the soil and applying electric field to produce electroosmotic seepage,the soil drainage is consolidated to increase the strength.Compared with the traditional consolidation method,the advantage of the consolidation method is that it can make quick consolidation of soft clay,which can greatly shorten the construction period and achieve good reinforcement effect.However,electroosmosis needs much more electric energy,so it is hard to be applied in the field engineering.This paper aims to reduce the energy consumption of electroosmosis and improve the efficiency of electroosmosis.Based on the different conditions of electroosmosis test,the improved Miller Soil Box test device and the self-made electroosmosis geotextile test device are used to carry out one-dimensional and two-dimensional electroosmosis tests on the characteristics of soft clay.The main conclusions are as follows:1.One-dimensional electroosmosis test was carried out with the improved Miller Soil Box test device to study the influence of water content on the electroosmotic characteristics of soft clay during the test.The experimental results show that the conductivity of soil under the different initial water content(42%-80%)decreases gradually with the increase of electrical time,and the contents of electrical conductivity are generally close.The amount of electroosmosis migration always fluctuates around a certain value,and the higher the water content,the lower the electroosmosis migration;the energy consumption coefficient decreases with time and then maintains a stable rule.2.The effect of salt content on the electroosmotic characteristics of soft clay is studied by one-dimensional electroosmosis test in the electroosmosis process.The experimental results show that the conductivity of the soil increases at first and then gradually decreases to the stationary rule with the increase of the electrified time in different salt content conditions(6g/L-12g/L).In the early stage of experiment,the conductivity increased with the increase of salt content,and gradually decreased in the later stage of experiment;the electroosmosis migration fluctuates around a certain value in the early stage of the test,and the energy consumption coefficient increases with time,and the rate of change is slower.3.Using self-made electroosmotic soil test device to carry out two-dimensional electro osmosis test of soft clay under the conditions of continuous electrifying and cyclic electrifying.The experimental results show that the average energy consumption increases with the increaseof the power time,and the average energy consumption level under the cyclic electrifying condition is lower than it is under the continuous electrified condition,so the energy consumption can be reduced to a certain extent.4.Based on the GDS ring shear apparatus,the samlple of soil in different distance from the cathode was selected to carry out the ring shear test.The residual strength,the cohesive force and the friction angle of the soil before and after the electroosmosis were compared and analyzed.The experimental results showed that the residual strength of the soil before electroosmosis was lower than the residual strength of the soil after electroosmosis;the friction angle of the soil before electroosmosis and the friction angle of the soil after electroosmosis are similar,and the cohesive force of soil before electroosmosis is similar to the cohesive force of the cathode area after electroosmosis,and it is lower than the cohesion of the soil area such as the distance cathode 200 mm and 400 mm after the electroosmosis.5.Based on the basic assumption of electroosmosis theory,the coupling control equation of soil electroosmosis under the effect of DC electric field is established,and the one-dimensional electroosmosis equation is derived according to the space boundary condition.The one-dimensional electro osmotic consolidation hole pressure solution under the condition of electroosmosis boundary and the initial electroosmosis condition is obtained respectively.