Improvement of shear strength and compressibility of soft clay stabilized with lime columns

Soft clay improvement using lime columns is an effective and economic method; which used mainly for enhancing the engineering properties of soft soil, reducing settlement and increasing shear strength. Improvements in engineering properties of soft clay can be achieved instantaneously with small additions of lime to soft soils. However, the effectiveness of this improvement depends on the quantity and type of lime as well as the mineralogical composition of soil. In this paper, the behavior of soft clay improved with lime columns has been studied. A series of large scale direct shear box tests were carried out with different number of lime columns, diameter, and different curing periods. Experimental study was carried out on both single and a group of lime columns. The results showed that the group of columns increased the shear resistance of soft clay soil with lesser horizontal deformation. Shear strain decreased by 28% and 47% in case of using 1 and 4 lime columns respectively after 7 days curing. Meanwhile, increasing the lime column diameter was found to increase the shear strength of soft clay and improve its compressibility. Finally, the shear strength was found to be increased by 53% when using a single lime column, while when using a group of 4 lime columns with diameter/length (D/L) ratio equals 0.28, the shear resistance is duplicated compared to the case of soft clay without lime columns.