Electro-Osmotic Consolidation Studies on Peat and Clayey Silt Using Electric Vertical Drain

Peat and soft soil deposits are abundant in Malaysia. Studies using electrokinetic geosynthetics (EKG) such as prefabricated electric vertical drains (EVD or ePVD) have shown the potential for the application of these materials in electrokinetic strengthening of soft clays and increasing solids content in mining tailings and sludges. There are no studies reported on the effectiveness of electro-osmosis using EVD in peat. Laboratory experiments were carried out to investigate the effectiveness of electro-osmotic stabilization of two peat samples and a slightly organic clayey silt sample, from the North Sarawak region. Commercially available EVD was used to induce electro-osmosis and drainage of pore water. The influence of voltage gradient, organic content, initial water content, anode–cathode configuration and presence of roots on electro-osmotic consolidation was investigated. Electro-osmotic consolidation using EVDs was effective in the improvement of peat, over a large range of initial water contents. An increase in the voltage gradient generally improved consolidation. The maximum voltage gradient for optimum results appeared to be in the region 120 V/m. The 2anodes-1cathode configuration performed better than the 1anode-1cathode configuration. The presence of roots reduced the electro-osmosis effect.

[1]  D. T. Bergado,et al.  Innovations and performances of PVD and dual function geosynthetic applications , 2004 .

[2]  C. Ou,et al.  Soil improvement using electroosmosis with the injection of chemical solutions: field tests , 2009 .

[3]  Inthuorn Sasanakul,et al.  ELECTRO-OSMOTIC CONSOLIDATION OF SOFT BANGKOK CLAY USING COPPER AND CARBON ELECTRODES WITH PVD , 2003 .

[4]  Bujang B. K. Huat,et al.  Engineering Properties and Compressibility Behavior of Tropical Peat Soil , 2007 .

[5]  James K. Mitchell,et al.  Fundamentals of soil behavior , 1976 .

[6]  Nader Shariatmadari,et al.  Role of organic matter on electroosmotic properties and ionic modification of organic soils , 2009 .

[7]  J. Q. Shang.  Zeta potential and electroosmotic permeability of clay soils , 1997 .

[8]  A. M. Hee,et al.  A FIELD TRIAL FOR SOFT CLAY CONSOLIDATION USING ELECTRIC VERTICAL DRAINS , 2004 .

[9]  T F Wong,et al.  Design parameters for soft ground in Malaysia , 1988 .

[10]  Serge Leroueil,et al.  Embankments on Soft Clays , 1990 .

[11]  Guy Lefebvre,et al.  A case record of electroosmotic consolidation of soft clay with improved soil-electrode contact , 2004 .

[12]  M. H. El Naggar,et al.  Effect of electro-osmotic treatment on piles , 2004 .

[13]  Andy Fourie,et al.  Dewatering of mine tailings using electrokinetic geosynthetics , 2007 .

[14]  Colin J F P Jones,et al.  Electrically conductive geosynthetics for consolidation and reinforced soil , 2001 .

[15]  Julie Q. Shang,et al.  Electokinetic dewatering of clay slurries as engineered soil covers , 1997 .

[16]  A. S. Mujumdar,et al.  Laboratory Experiments on Electroosmotic Dewatering of Vegetable Sludge and Mine Tailings , 1996 .

[17]  Gholamreza Mesri,et al.  Engineering Properties of Fibrous Peats , 2007 .

[18]  Stephanie Glendinning,et al.  Treatment of sewage sludge using electrokinetic geosynthetics. , 2007, Journal of hazardous materials.

[19]  B. A. Chappell,et al.  Electro-Osmosis Applied to Unstable Embankment , 1975 .

[20]  N. C. Lockhart,et al.  Dewatering coal washery tailings ponds by electroosmosis , 1984 .

[21]  Bozena Paczkowska,et al.  Electroosmotic introduction of methacrylate polycations to dehydrate clayey soil , 2005 .

[22]  J. Q. Shang,et al.  Electrokinetic improvement of soft clay using electrical vertical drains , 2008 .

[23]  Krishna R Reddy,et al.  Electroosmotic dewatering of dredged sediments: bench-scale investigation. , 2006, Journal of environmental management.

[24]  J. Moum,et al.  APPLICATION OF ELECTRO-OSMOSIS TO A FOUNDATION PROBLEM IN A NORWEGIAN QUICK CLAY , 1967 .

[25]  K. Y. Lo,et al.  Field test of electroosmotic strengthening of soft sensitive clay , 1991 .

[26]  Stephanie Glendinning,et al.  Treatment of lagooned sewage sludge in situ using electrokinetic geosynthetics , 2008 .

[27]  Nader Shariatmadari,et al.  Physicochemical sensitivities of tropical peat to electrokinetic environment , 2010 .

[28]  D. T. Bergado,et al.  Electro-osmotic consolidation of soft Bangkok clay with prefabricated vertical drains , 2000 .

[29]  R. H. Sprute,et al.  Electrokinetic densification of solids in a coal mine sediment pond - A feasibility study (in two parts). 2. Design of an operational system , 1988 .

[30]  J. Q. Shang,et al.  Effects of electrode materials and current intermittence in electro-osmosis , 2001 .

[31]  Julie Q. Shang,et al.  Electrokinetic dewatering of a phosphate clay , 1997 .

[32]  Neville C. Lockhart.  COMBINED FIELD DEWATERING: BRIDGING THE SCIENCE-INDUSTRY GAP , 1992 .

[33]  Claude A. Fetzer,et al.  ELECTRO-OSMOTIC STABILIZATION OF WEST BRANCH DAM , 1967 .