Influence And Mechanical Properties Of Electrochemically Solidified Soft Clay

Due to the low permeability coefficient,the soft soil has the characteristics of high water content,low water permeability and low shear strength,so it is not easy to carry out drainage reinforcement treatment.Compared with the traditional soft clay foundation reinforcement method,the electroosmosis method can effectively increase the electric permeability coefficient,thus speeding up the drainage consolidation and shortening the construction period,so it is an effective method for the consolidation of soft clay.In the construction process of soft clay foundation,it is easy to cause the damage of foundation instability and uneven settlement,so it is necessary to reinforce it.In this paper,based on the existing research results,a self-made electroosmosis test device was developed to explore the consolidation process of soft clay by single electroosmosis and electroosmosis combined with solution method,and the mechanical properties of soft clay after electroosmosis were studied by combining micro and macro.The self-made one dimension groove electroosmosis experiment,electroosmosis indoor experiment study,to explore the different electric potential gradient（i.e.,0.5 V/cm,1.0 V/cm and 1.5 V/cm）under the action of single electroosmosis experiment and the electroosmosis joint solution method,the influence of drainage consolidation of soft clay,and the current in the process of electroosmosis,displacement and settlement,the electric potential measurement,and the electroosmosis anode,middle and cathode three places after the moisture content of soil and the final energy consumption per unit of drainage were analyzed;Different concentrations of Ca Cl₂,Na OH and Na₂Si O₃mixed solution were injected into the anode and cathode respectively,and the difference between the electroosmotic test and the single reinforcement of soft clay was analyzed.Test results show that the joint solution electroosmosis method is to a single electroosmosis eventually current,displacement and settlement are larger,eventually the same location of moisture content was lower than those of single electroosmosis,also due to the increase of ion content in the soil,increase the electromigration effects of ions,increasing the conductivity of the soil in order to reduce the resistance,so the final energy consumption per unit of drainage was lower than those of single electroosmosis.In order to explore the influence of different confining pressures on the strength of soft clay after electroosmosis,the strength comparative analysis of soils under different confining pressures（50 k Pa,100 k Pa and 200 k Pa）and consolidation compression test were conducted in this paper to explore its deformation and mechanical properties.The results show that the electroosmosis combined solution method can effectively improve the strength of the soil at the anode and the intermediate position,and the strength distribution of the soil under the combined action of the two is more uniform;Scanning electron microscopy（SEM）was used to analyze the microstructure of soil,and then the strengthening mechanism of electroosmotic combined solution method was analyzed by combining macroscopic and microscopic methods.It is found that with the increase of salt solution concentration,the internal pore ratio of soil decreases and the cohesion increases,indicating that the electrochemical method can effectively fill the soil pores compared with the single electroosmosis method.In order to verify the finite element numerical method for the full coupling analysis of soil electroosmosis consolidation,a finite element model was established by using Comsol Multiphysics simulation software based on the multi-field coupling control equation of electroosmosis consolidation.The simulation results show that the spatiotemporal variation process of the excess pore water pressure of normalized anode is consistent under three kinds of potential gradient conditions.When the potential gradient increases from 0.5 V/cm to 1.0V/cm,the development of excess pore water pressure is more obvious than that when the potential gradient increases from 1 V/cm to 1.5 V/cm.The greater the potential gradient is,the better it is.The suitable potential gradient can be selected for electroosmosis test in combination with the predicted maximum overstatic negative pore pressure and consolidation settlement value.