## 2 Experimental Analysis  
### Material Characteristics  
Soft clay, crushed stones, and two varieties of geotextiles (G1 and G2) were employed as the materials in this study. The stone materials and clay were classed as GP and CL according to the Unified Soil Classification System. Crushed stone and geotextiles were chosen to improve the characteristics of the soft clay, and the materials were selected because of their feasible availability. Similar materials have been chosen by various researchers [11; 13; 19; 34]. The numerous different characteristics of both materials are presented in Tables 1 and 2. To estimate the water content that is equivalent to a clay undrained a shear strength of 20 kPa, a set of unconfined compressive strength (UCS) experiments were performed on a cylindrical sample with a diameter of 38 mm and a height of 76 mm. Moreover, the laboratory vane shear test was performed to decide the water content that corresponded to a particular undrained shear strength, which was performed according to Indian Standard IS2720 part 30 [44]. Various test samples were prepared using different water contents, and the undrained shear strength was determined [44]. Figure 1 shows the variation in the undrained shear strength in response to the moisture content from the results of the laboratory vane shear test. The clay's moisture content was calculated as 26.13% (Figure 1), which was maintained throughout the experiments. The stone column material consisted of crushed stone aggregates that had diameters that varied from 2 to 10 mm.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Characteristics** & **Data** \\ \hline Liquid Limit & 50\% \\ \hline Plastic Limit & 27\% \\ \hline Specific Gravity & 2.56 \\ \hline Plasticity Limit & 23\% \\ \hline Shrinkage Limit & 10\% \\ \hline Optimum Moisture Content & 19.23\% \\ \hline \hline \end{tabular}
\end{table}
Table 1: Characteristics of soft clay.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Characteristics** & **Data** \\ \hline Maximum Dry Unit Weight & 17.16 kN/m3 \\ \hline Bulk Unit Weight at 26.13\% water content & 18 kN/m3 \\ \hline Undrained Shear Strength & 20 kPa \\ \hline Unified Classification System & CL \\ \hline \hline \end{tabular}
\end{table}
Table 1: _Cont._  
Figure 1: Clay’s undrained shear strength variation with moisture content.  
Two varieties of polypropylene (non-woven type) geotextiles were considered as a strengthening substance in the proposed testing. Table 3 shows the value of the tensile strength of considered geosynthetics as measured by standard wide-width tension testing.  
Figure 2 shows a diagram of the three different kinds of columns employed in this study, which are Ordinary stone columns (OSC), Vertically reinforced stone columns (VESC), and Horizontally reinforced stone columns (HRSC) for different lengths of reinforcement considered in this study.  
Figure 2: Schematic of (**a**) OSC, (**b**) VESCs with various L\({}_{r}\), (**c**)HRSCs with various geosynthetic arrangements.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & **Geotextile 1 (G1)** & **Geotextile 2 (G2)** \\ \hline Ultimate tensile strength (kN/m) & 8 & 12 \\ \hline Strain at ultimate strength (\%) & 52 & 36 \\ \hline Tensile modulus (kN/m) & 14 & 31.5 \\ \hline Ultimate tensile strength from tests with seam (kN/m) & 7 & 11.4 \\ \hline Strain at ultimate strength (\%) from tests with seam & 46.5 & 30.8 \\ \hline Tensile modulus (kN/m) from seam tests & 14.8 & 35 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Properties of Geosynthetics.