The Effect Of Salt Solution On Vacuum Preloading And Electro-osmosis

With the rapidly developing economy and booming population of coastal cities,Land reclamation has been prosperously conducted in China's coastal cities in recent decades.Marine clay dredged from the seabed serves as the main filler material.It is typically characterized by high water content,high compressibility,extremely low undrained shear strength,and low hydraulic permeability.Hence,the treatment of such soils has become imperative in geotechnical engineering.The most common method of increasing the consolidation of dredged slurry is vacuum preloading;however,the characteristics of dredged slurry,particularly low hydraulic permeability,lead to technological problems such as a long consolidation period,severe clogging in the plastic vertical drains,The drainage rate of electro-osmosis depends primarily on the electrical permeability of the dredged slurry instead of the hydraulic permeability,and the effective depth is deeper than that found in any other foundation treatments.To improve the consolidation of dredged slurry,a combined method of vacuum preloading and electro-osmosis consolidation was applied to a dredged slurry.This paper takes the dredged slurry of Wenzhou as research object to study these uncertain parameters by laboratory test.Through the indoor large-scale model test,the effect of salt solution on vacuum pre-compression combined with electro-osmosis was studied to achieve the goal of saving cost and improving soil treatment effect.The grouting test results show that the anions are the same,and the higher the cation chemical valence,the better the test effect.The inorganic flocculant test show that the optimum inorganic flocculant FeCl3 is 0.8% of the dry weight of the soil;the addition of inorganic flocculant can effectively improve the amount of water in vacuum preloading stage and electroosmotic stage;obtaining higher and more uniform soil strength;Adding 0.8% Ca(OH)2 to the soil can change the characteristics of the soil and accelerate the hardening of the sludge.Compared with the ferric chloride,it can reduce the corrosion and energy consumption of the electrode,but the flocculation effect and the displacement are small.The experimental test analysis of the types of salt solution,the amount of these important test parameters can effectively help the application of the technology in the field practice,increase the ground treatment effect reduces the cost at the same time.