IMPROVEMENT OF BOSTON BLUE CLAY USING ELECTROOSMOTIC CONSOLIDATION WITH POLYPROPYLENE FIBERS: A MODEL EXPERIMENT

Electro-osmotic consolidation method is a foundation treatment method for soft clay. However,electro-osmotic consolidation may cause the cracks generation in soft clay,which will reduce the electro-osmotic flow channel and the electro-osmotic consolidation effect. Therefore,this paper mixed polypropylene fiber with Boston blue clay during the electro-osmotic consolidation,which improved the reinforcement effect. In this paper,a self-made electro-osmotic consolidation test system was used to monitor the current,potential distribution,water content and crack generation during electro-osmotic consolidation. After electro-osmotic consolidation,the pH value,Cl^- molar concentration,water content and undrained shear strength distribution of Boston blue clay were measured. Based on the electro-osmotic consolidation theory,conductivity theory,ion transport theory and electrolysis theory,the results and conclusions are as follows: (1)The suction generated in the process of electro-osmotic consolidation will cause cracks in Boston blue clay,and mixing 0.05% and 0.1% polypropylene fiber can reduce the degree of crack propagation. Moreover,cracks can be eliminated by mixing 0.15% and 0.2% polypropylene fiber; (2)During the electro-osmotic consolidation,the mixing of polypropylene fiber is beneficial to ion migration and electrolysis reaction. The results show that the pH value decreasing and the Cl^-molar concentration increasing were observed near the anode after mixing polypropylene fiber; (3)With the mixing of polypropylene fiber,the electro-osmotic flow and drainage of Boston blue clay can be significantly increased. After the electro-osmotic consolidation,the maximum undrained shear strength of 0.2% polypropylene fiber is 477.8% higher than that of 0% polypropylene fiber.