Weak clayey soils often exhibit low bearing capacity and excessive settlement, resulting in unsafe and uneconomical foundation systems. Soil reinforcement using geosynthetics such as polypropylene (PP) geogrids has become a widely accepted ground improvement technique. However, acrylic reinforcement materials possess higher stiffness and improved load transfer characteristics, which may provide better settlement control and bearing resistance. This study presents a comparative investigation on the bearing capacity improvement of clay soil reinforced with polypropylene geogrid and acrylic sheet reinforcement using laboratory model plate load tests. Experimental tests were conducted on unreinforced soil, single-layer reinforced soil, and double-layer reinforced soil configurations. The performance was evaluated based on ultimate load carrying capacity and settlement behavior. Results indicated that acrylic double-layer reinforcement exhibited the highest improvement, increasing the ultimate load from 14 kN to 17.8 kN while reducing settlement from 14.8 mm to 8.6 mm. Polypropylene geogrid reinforcement also enhanced soil performance, but acrylic reinforcement demonstrated superior stiffness and confinement characteristics. The study confirms that acrylic reinforcement can serve as an effective alternative reinforcement material for foundation applications in weak clay soils.

Keywords: Clay soil, Polypropylene geogrid, Acrylic reinforcement, Bearing capacity, Settlement, Plate load test.