Experimental Study On The Influence Of Nanomaterials On Electroosmosis For Consolidation Soft Clay

Soft clay is not suitable to be used as construction land because of low permeability,low bearing capacity and high water content.At present,electroosmotic drainage method is an effective method to reduce the water content of fine granular soil.However,the efficiency of this electrochemical technology still needs to be further improved for practical application.Nanomaterials,as one of the most promising materials emerging in recent decades,can significantly improve the physical and mechanical properties of soil under low dosage.In this paper,nanomaterials are applied for reinforcement of clay based on its unique properties.A series of laboratory electroosmosis tests were carried out by combining nanomaterials with electroosmosis drainage technology to explore the influence and related mechanism of the combination,which provides a new idea for the electroosmosis method on strengthen soft soil foundation.The main research contents and achievements are as follows:(1)Carbon nanotubes and silica nanoparticles with different particle sizes were used to modify clay.It is found that nanomaterials can increase the liquid limit of soil,and the liquid limit increases with the increase of the content of nanomaterials.The unconfined compressive strength increases linearly with the addition of nano-materials,and the maximum compressive strength of carbon nanotubes is obtained with the same dosage.The compressive strength is improved,and the brittleness of the sample increases.Meanwhile,the final compressibility and compressibility coefficient of the modified soil are obviously reduced.Finally,the change of macroscopic mechanical properties is explained through the analysis of microstructure.(2)A self-designed electroosmotic drainage device was used to explore the related laws of soil reinforcement under the combination of nanomaterials and electroosmotic method.The results show that the addition of nanomaterials can reduce the resistance and the development of cracks of soil,which finally promote the drainage volume.The introduction of electrolyte solution with appropriate volume will further improve the effect of electroosmotic reinforcement on this basis.(3)Nanosilica sol was selected as anodic fluid in the process of electroosmosis and these charged nanoparticles can be driven into the soil by electric field.Electroosmosis tests confirmed that the drainage and shear strength can be improved under the low energy consumption.It is proved that nanosilica particles can migrate from anode to cathode and fill the soil pores by means of microstructure test and elemental analysis,which provides a noninvasive reinforcement method for nanomaterials combined with electroosmotic drainage method.