Numerical analysis of soil reinforced by sand columns using different installation methods

This study involves a finite element numerical simulation of laboratory tests conducted on small-scale models. The tests involved the installation of columns using different techniques: without soil displacement and without column compaction (WR-NC), and without soil displacement but with column compaction (WR-WC). The reinforced soil masses were then subjected to a uniform 150 kPa load. A comparison between the numerical and experimental results showed excellent agreement, validating the simulation. Following this validation, a parametric analysis was carried out to examine the effects of the various parameters on the behavior of the reinforced soil masses. In the first method, three different column diameters were analyzed, focusing on the effects of diameter (area replacement ratio), column length, and geogrid containment benefits. In the second method, three levels of compaction pressure were applied during the column installation. The study evaluated the impact of column installation techniques on the behavior of the reinforced masses. The findings indicate that settlement reduction is proportional to the increase in area replacement ratio and column length. Additionally, confining the columns with geogrid was shown to be effective in further reducing settlements. The results also revealed that increasing compaction stress leads to greater radial expansion of the columns, which densifies and stiffens the surrounding soil, thereby reducing settlement. Overall, the study concludes that column installation techniques significantly influence the behavior of reinforced soil masses.