Laboratory investigations on geogrid-, geotextile-, and geocell- stabilised moderately swelling subgrades

Expansive subgrades undergo moisture-induced volumetric changes due to water infiltration from the pavement surface and shoulders, leading to differential subgrade heave and nonuniform swell pressures on the overlying pavement layers. This study evaluates the effectiveness of different geosynthetic reinforcements in mitigating differential subgrade heave, quantified in terms of potential vertical rise (PVR) and surface heave. Largescale model experiments were conducted in a 1.5 × 1.5 × 1.1 m test chamber, where swell pressures ranging from 0 to 450 kPa were applied at the subgrade level using a 250 mm diameter circular plate. Both unreinforced and reinforced pavement sections were investigated using woven biaxial polyester geogrids and woven polyester geotextiles with ultimate tensile strengths of 100 and 200 kN/m, along with polyethylene geocells having cell depths of 150 and 200 mm. Geocells showed the highest PVR reduction (≈67%), followed by geotextiles (56%) and geogrids (28%) at 450 kPa swell pressure.