Field evaluation of geocell parameters for enhancing performance of unpaved roads

This study evaluates the impact of key geocell parameters on the performance of reinforced pavement sections over problematic soils in Dholera, Gujarat, India. A total of seven test sections were built, comprising one unreinforced and six reinforced (RE) sections with varying geocell heights ( H = 75, 100, and 150 mm) and weld spacings (SW = 330 and 356 mm). Field testing included falling weight deflectometer and full-scale instrumented plate load tests. Results indicate that reinforced sections with lower weld spacings and greater geocell heights (SW330-H150) demonstrated significantly higher bearing capacity compared to those with larger weld spacings and smaller geocell heights. The subgrade stress dispersion angle for reinforced sections ranged from 40.73° to 51.40°, while the maximum modulus improvement factor observed was 2.31. Reinforced sections achieved service life ratio values between 2.07 and 2.38, signifying extended service life over expansive soils. Strain analysis indicated that geocells with greater weld spacing and reduced height experienced higher strain levels. Notably, the RE sections SW330-H100 and SW356-H150 exhibited similar performance, while SW330-H75 showed comparable results to SW356-H100. These findings emphasize the importance of optimizing geocell height and weld spacing for enhanced pavement performance, providing key insights for pavement design in challenging soil conditions.