Use of goesynthetics to reinforce low volume roads

Abstract

The research described herein was originated to investigate the reinforcement function of geosynthetics for typical Minnesota low-volume roadways. To this end, a series of numerical experiments were conducted using the finite difference program FLAC (1993). The tests consisted of a static, circular, 9 kip loading over a variety of typical surfaced and unsurfaced road cross sections that were reinforced with geotextiles and geogrids. The results are shown in terms of percent normalized deflection reduction and percent normalized accumulated standard axle load to a serviceability level of 2.5 (ASAL2.5) increase. Additionally, the effect of a geosynthetic reinforcement layer on the horizontal stress distribution is illustrated. The results of the study indicate that the addition of a geosynthetic does provide reinforcement to the roadway as long as the geosynthetic is stiffer than the subgrade material. However, for most of the cases studied, the benefit in terms of deflection reduction, was very small. Only for the poorest quality subgrades was the reinforcement benefit substantial.