Experimental Study On Consolidation Of Silty Soil By Electroosmosis Combined With Surcharge Loading

Electroosmosis method is an effective method for soft soil consolidation treatment,applying direct current field to make it through the soil drainage consolidation so as to improve strength and the drainage rate has nothing to do with the soil particle size.Also,it is considered to deal with high water content,low permeability,soft soil.However,the electroosmosis method has not been widely used in practical engineering.In this paper,based on the essence of electroosmosis and electroosmosis test conditions,improving Miller Soil Box model Box and self-made electroosmosis model Box are used to conduct the electroosmosis test from the macro and micro perspectives of Soil.The main conclusions are as follows:1.Improving Miller Soil Box model Box is used to conduct electroosmosis tests under different water contents.The apparent pore ratio and average pore area of soil increase with the increase of water content.2.The electroosmosis test is carried out based on different electrification time.The test results show that: at different electrification time(12h,16 h,20h,24h),the cumulative displacement of soil present a certain timeliness.The apparent pore ratio and average pore area of the soil decrease with the increase of the electrification time.3.A self-made model box is used to carry out the combined load test of single electroosmosis and electroosmosis.The test results showe that: in the control test of single electroosmosis and electroosmosis combined load,the final cumulative displacement and drainage rate of the combined load of electroosmosis are larger than that of the single electroosmosis combined load,and the drainage rate had obvious advantages in the middle and early stage.The cracks and the final settlement after the electroosmotic combined surcharge are smaller than the single electroosmotic test,which indicates that the final reinforcement effect of the combined surcharge is good.The shear strength of soil after electroosmosis combined with heap load test is larger than that of single electroosmosis test,and the shear strength of cathode area in eachtest is smaller than that of other areas.The apparent pore ratio and average pore area of soil mass after the combined electroosmosis test were smaller than that of single electroosmosis.The pore structure of soil is affected by both water content and vertical load provided by heap load.4.Based on the basic assumption of electroosmosis theory,the governing equation of soil electroosmosis coupling under direct current electric field is established,and the governing equation of one-dimensional electroosmosis is derived according to spatial boundary conditions.Combined with the boundary conditions of electroosmosis and initial conditions of electroosmosis,the pressure solution of one-dimensional electroosmotic consolidation hole under combined surcharge conditions of electroosmosis is obtained.