Full-Scale Field Study of Geosynthetics Used As Subgrade Stabilization

Full-scale field test sections were constructed to evaluate the performance of several geosynthetics commonly used for subgrade stabilization. A sandy clay soil was uniformly prepared as a weak, artificial roadbed material and a 20-cm-thick aggregate layer was compacted over the geosynthetics. Trafficking was provided by a fully loaded tandem-axle dump truck. Longitudinal rut depth was monitored throughout the trafficking period to evaluate performance. Based on an empirical analysis, the results showed that the welded geogrids, woven geogrids and the stronger integrally formed geogrid product seemed to provide the best overall performance, while the two geotextile products and the weaker integrally formed geogrid provided significantly less stabilization benefit. Furthermore, this performance is likely to be directly related to the tensile strength of the materials in the cross-machine direction. Failure of the woven geotextile and weaker integrally formed geogrid was due to pullout and longitudinal rupture of these materials, respectively. Additional work is needed to more fully understand which geosynthetic material parameters are most relevant in these situations.