Sustainability Evaluation of Geosynthetic Stabilized Soft Subgrade Soil in Unpaved Test Sections: Fid-Bau Portal

Sustainability Evaluation of Geosynthetic Stabilized Soft Subgrade Soil in Unpaved Test Sections

Abu-Farsakh, Murad / Hanandeh, Shadi / Tang, Xiaochao / Chen, Qiming

This paper presents the findings from an ongoing research study aimed to evaluate two recently developed geosynthetic products, a triaxial geogrid and a high-strength woven geotextile for reinforcing/stabilizing sustainable roads constructed over soft subgrade soil. A total of six full-scale test lane sections were constructed, among which two sections were reinforced by one and two layers of triaxial geogrids, respectively; while high strength geotextile was used to reinforce two of the other sections with different aggregate layer thicknesses. The rest of the two sections were left as control sections, of which one section was constructed over 30-cm thick sand embankment representing the common practice in Southern Louisiana. The unpaved test sections were subjected to a full-scale moving wheel load applied by the accelerated loading facility (ALF). A variety of instrumentations were used to measure the load-associated and the environment-associated pavement responses and performance. Results of the full-scale testing on the unpaved test sections demonstrate the benefits of geosynthetic reinforcement/stabilization in reducing the permanent deformation in the pavement structure. The test sections’ resilient behavior did not seem to be influenced by the presence of geosynthetics. It was also found that, instead of the soft soil subgrade, the aggregate layer is the primary contributor to the total permanent deformation/surface rutting of the unpaved sections under the testing conditions in this study. Geosynthetics were mobilized and generally exhibited a strain around 0.2%.