An analytical solution for two-dimensional vacuum preloading combined with electro-osmosis consolidation using EKG electrodes

Abstract

China is a country with vast territory, but economic development and population growth have reduced the usable land resources in recent years. Therefore, reclamation by pumping and filling is carried out in eastern coastal regions of China in order to meet the needs of urbanization. However, large areas of reclaimed land need rapid drainage consolidation treatment. Based on past researches on how to improve the treatment efficiency of soft clay using vacuum preloading combined with electro-osmosis, a two-dimensional drainage plane model was proposed according to the Terzaghi and Esrig consolidation theory. However, the analytical solution using two-dimensional plane model was never involved. Current analytical solutions can’t have a thorough theoretical analysis of practical engineering and give relevant guidance. Considering the smearing effect and the rectangle arrangement pattern, an analytical solution is derived to describe the behavior of pore-water and the consolidation process by using EKG (electro-kinetic geo synthetics) materials. The functions of EKG materials include drainage, electric conduction and corrosion resistance. Comparison with test results is carried out to verify the analytical solution. It is found that the measured value is larger than the applied vacuum degree because of the stacking effect of the vacuum preloading and electro-osmosis. The trends of the mean measured value and the mean analytical value processes are comparable. Therefore, the consolidation model can accurately assess the change in pore-water pressure and the consolidation process during vacuum preloading combined with electro-osmosis.

Study on the Interaction between the Reduction and Remediation of Dredged Sediments from Tai Lake Based on Vacuum Electro-Osmosis

“…For the reduction of contaminated dredged sediment, some scholars have introduced vacuum preloading in the field of foundation treatment into sediment treatment. The advantage of this method is the simple construction technology and low cost [7][8][9]. However, as a traditional mechanical dehydration method, the vacuum preloading method has a long construction period, and the treatment effect is difficult to meet the requirements [10].…”

Numerical analysis on ground improvement of vacuum preloading with prefabricated radiant drain

“…Some new vacuum preloading technologies have been extensively studied, such as vacuum preloading combined with surcharge preloading (Ye et al 2018), air booster vacuum preloading (Cai et al 2018), straight-line vacuum preloading without sand cushion (Miao et al 2015), electroosmosis vacuum preloading (Wang et al 2016), pharmaceutical vacuum preloading (Wu et al 2017). The main improvement mechanisms are summarized as follows: (1) drainage pipeline is used as horizontal drainage system to replace sand cushion (Shi et al 2018); (2) pressure difference around PVD is increased to accelerate soil consolidation (Xie et al 2019); (3) directional movement law of particles is changed to prevent PVD from silting up (Chai and Rondonuwu 2015); (4) particle size distribution is changed to boost soil drainage capacity (Shen et al 2017).…”

Land reclamation using soft clay fill and vacuum preloading via horizontal drainage enhanced geotextile sheets

“…Literature Review 33 (1948,1983), Bjerrum et al (1967), Esrig & Gemeinhardt (1967), Fetzer (1967, Lo et al (1991a&1991b), Shang (1998), Su & Wang (2003), Hu et al (2012, Wu & Hu (2011), Lee (2015), Lamont-Black et al (2016) and Shen et al (2017). The electroosmotic consolidation as a soil improvement technique has been applied in projects such as stabilization of earth dams, railways embankment, slopes and pile foundation.…”

“…The electro-kinetic flow rate is 100 to 10,00 times greater than the hydraulic flow rate in fine-grained materials (Jones et al, 2008). Some consolidation tests combining the vacuum preloading with electro-osmosis have been conducted (Lo et al, 1991b;Shang, 1997;Wang & Vu, 2010;Jeyakanthan et al, 2010;Shen et al, 2012;Shen et al, 2017;Sun et al, 2017;Wang et al, 2016). Liu (2014) studied the consolidation process combining the electro-osmosis, vacuum pressure and surcharge.…”

“…The EKG combines the electro-kinetic phenomena of electro-osmosis, electrophoresis and associated electro-kinetic with the traditional geosynthetics functions of drainage, filtration, containment and reinforcement. The electrically conductive PVDs was developed by using copper electrodes in the electrically conductive polymer cores of PVDs as shown in Figure 2.34(a) and (b) (Lee, 2015;Shen et al, 2017). The conductive polymer is made of the polymer and carbon powder.…”