Experimental Study On Multi-electro-osmosis Combined Drainage Of Soft Soil Foundation

Since Reuss,a former Soviet scientist,first discovered the electroosmotic phenomenon in soil by experiment in 1809,and Casagrande applied electroosmotic technology to the treatment of soft soil foundation in 1939,many scholars have studied the application of electroosmotic technology in the treatment of soft soil foundation.In recent decades,with the development and progress of economic technology,rapid and efficient drainage of soft soil foundation and deep soil drainage have become difficult problems in engineering construction,so electroosmosis method has attracted more and more attention.At present,how to use electro-osmosis method to quickly and efficiently drain water from soft soil foundation is an important content of research on electro-osmosis to solve the drainage problem of soft soil foundation.This paper summarizes the research status of electroosmosis method,introduces the drainage mechanism of electroosmosis method,advantages and disadvantages of electroosmosis method in soft clay foundation treatment.Based on the self-designed test device,a series of indoor and outdoor model electroosmotic drainage tests were carried out on soft clay 7 m deep underground in Shenyang Construction University.The main purpose of this study is to improve the drainage efficiency of electroosmotic treatment of soft clay and electroosmotic drainage of deep soil layers,providing guidance for the popularization of electroosmotic method and practical engineering application.The main work and research results are as follows:This paper is divided into three parts:First,the experimental study of drainage by the double electroosmosis systems.The double electroosmosis systems drainage test and the single electroosmotic drainage test were carried out.By comparing and analyzing the influence factors of the two groups of electroosmotic drainage tests,such as electroosmotic drainage volume,drainage time,energy consumption and water content change,it is concluded that the electroosmotic drainage effect of the double-level electroosmotic drainage test is better than that of the single-level electroosmotic drainage test.That is to say,the electroosmosis drainage test after multi-electroosmosis treatment improves the efficiency of electroosmosis drainage.Second,experimental study on electroosmosis drainage under insulated electrode plate.Five groups of electroosmotic drainage tests were carried out in this part.Five groups of basic electroosmotic drainage tests include the electroosmotic drainage test of the fully insulated electrode plate,the electroosmotic drainage test of the non-insulated electrode plate,the electroosmotic drainage test of the insulated anode plate,the electroosmotic drainage test of the insulated cathode plate,and the electroosmotic drainage test under the combination of the fully insulated electrode plate and the insulated cathode plate.The conclusions are as follows:the electroosmosis drainage test of insulated electrode plate can increase the amount of electroosmosis water and reduce energy consumption,but it can prolong the electroosmosis drainage time.The combined electroosmosis drainage test has the best electroosmosis effect.Then COMSOL is used to study the distribution and variation of the potential field of the plate electrode in vertical one-dimensional soil column test.Third,the design of electroosmosis drainage in deep soil layer is carried out step by step,and two-stage electroosmosis drainage test is carried out.Two sets of comparative tests are designed:one is the step-by-step electroosmotic drainage test of fully insulated electrode plate,the other is the step-by-step electroosmotic drainage test of common electrode plate.By comparing the drainage volume,drainage time,energy consumption and water content changes of the two groups,it is concluded that the step-by-step electroosmosis drainage test with fully insulated electrode plate can improve the electroosmosis drainage volume and reduce energy consumption.However,the electroosmosis time becomes longer and there is water under the first cathode plate in the step-by-step electroosmosis drainage test.