Experimental Study on Improvement of Soft Clay Using Sand Columns

Sand Compaction Piles (SCP) commonly known as Sand Columns (SC) now has been vastly used for reinforcing the range of soft soils. The installation of sand columns results in enhancing the ultimate bearing capacity of soft soil, increase the rate of consolidation, prevention of liquefaction in loose sandy soils and provide lateral resistance against the horizontal movement. This research aims at investigating the effects of floating columns in clayey soil with silty deposits by developing small scale laboratory models. The laboratory tests were conducted on a circular column of 37 mm diameter and results of the treated ground are compared to the untreated ground. The effects of sand columns on soils of different shear strengths (low-medium- high), slenderness ratio (L/D) of columns and different loading pattern are investigated. Group effect was also investigated by varying the spacing between the columns. The equivalent entire area of test model was loaded to determine the stiffness of composite ground and axial capacity of sand column was determined by loading the column area alone. Based on current study, it was concluded that sand column can significantly enhance the engineering properties of soft clayey soil. Also, the group effect was studied and it was concluded that by increasing the spacing between the columns, the group efficiency decreases. The axial capacity of sand columns decreases while increasing the spacing between the columns.