Experimental study of granular platforms reinforced by geosynthetics over soft subgrade

A series of large-scale laboratory tests was conducted to evaluate the impact of geotextile reinforcement on the performance of unpaved roads. An experimental protocol was established, detailing the preparation of the road base soil, installation of geotextiles, and soil compaction procedure, and then implemented. Seven unpaved road sections were successively tested under vertical cyclic loading (plate load tests) and two under traffic loading (using a Simulator Accelerator of Traffic or SAT) in a large experimental box (1.8 m in width, 5 m in length, and 1.1 m in height). Two road base thicknesses and two geotextiles with two different stiffness values were tested. The results demonstrated the effectiveness of geotextile reinforcement, with findings highlighting the influence of road base thickness on reinforcement efficiency and the impact of loading type on performance outcomes. A comparative analysis was also conducted between the experimental results and design predictions from Giroud and Han’s (2004b) method.