Shear Strength Enhancement of Soft Clay Using Lime Columns: A Large-Scale Experimental Study

Soft clay soil is often classified as problematic due to its low shear strength and high compressibility, which can cause significant structural damage. To mitigate these issues, various soil stabilization techniques have been developed, including the use of lime columns, fly ash, and crushed bricks. In this study, a large-scale direct shear device was designed and constructed to evaluate the impact of lime column stabilization on the shear strength of soft clay. The shear box measured 20 cm in height, 30 cm in length, and 30 cm in width. A hydraulic piston applied shear force by moving the lower shear box while the upper box remained stationary. An automated data recording system monitored and recorded vertical forces, shear displacements, and horizontal shear forces throughout the testing process. A series of large-scale shear tests were conducted to assess the influence of lime column diameter on shear strength. The results demonstrated a significant improvement in shear performance with increasing column diameter. Specifically, the highest shear stress increase was observed when a 5.5 cm diameter lime column was used, resulting in a 73.3% increase in shear stress compared to untreated soft clay. Additionally, shear strain was notably reduced, further confirming the effectiveness of lime column stabilization. This study highlights the potential of lime columns as a cost-effective and efficient technique for enhancing the geotechnical properties of soft clay, making it a viable solution for foundation and infrastructure projects.