Characterization of Soil-Geosynthetic Interaction to Evaluate Reinforcement Location in Pavement over Expansive Soils: Fid-Bau Portal

Characterization of Soil-Geosynthetic Interaction to Evaluate Reinforcement Location in Pavement over Expansive Soils

Sarker, Debojit / Wang, Jay X.

Longitudinal cracks develop on roads constructed on expansive subgrade soils. For several decades, state DOTs in the US have used geosynthetic reinforcement to mitigate the environmentally incited longitudinal cracks. However, only a small amount of field data has been collected to date to understand the reinforcing mechanism. Recently, the virtual load method (VLM) has been developed to identify expansive soil-induced stresses in the geosynthetic-reinforced pavement. This research integrates the VLM in the study on a low-volume rural hot mix asphalt road in Texas to evaluate the effectiveness of the geosynthetics and different reinforcement location options within the pavement layers. The soil-geosynthetic interaction is characterized by applying the subgrade heave/shrinkage-induced reaction pressure to the ground surface, with the heave/shrinkage deformations being computed from the field-measured moisture content variations data. The optimum location of geosynthetic reinforcement is determined based on the tensile force absorption value by observing the two extreme weather conditions. The results demonstrate that the tensile force absorption increases by shifting the geosynthetics towards the bottom of the pavement and achieves the most significance when it is placed between the base layer and subgrade layer in the model.