Strength of Soft Soil Improved by Horizontal and Vertical Woven Geotextile

With increasing coastal development, construction on weak and soft soils has become more prevalent. Stone columns are a common technique for improving ground; their effectiveness in very soft clay is often limited because of the insufficient lateral support. To overcome this limitation, geotextile reinforcement is frequently employed to enhance the strength and stability of stone columns. This study investigates the effects of various geotextile reinforcement layouts, including vertical encasement, horizontal layering, and a combination of both, on the stone columns’ effectiveness in soft soil beds. Small-scale laboratory experiments were conducted in a model tank, with all stone columns designed to maintain a ratio of 4 for length-to-diameter to prevent bulging failure. The results indicated that woven geotextile significantly increases load-bearing capacity and reduces settlement. Among the tested configurations, the combined vertical and horizontal reinforcement yielded the best performance, whereas partial vertical encasement combined with moderately spaced horizontal layers provided an effective balance between performance and material efficiency. These findings offer valuable guidance for the cost-effective design of ground improvement solutions in soft soils.