Mechanistic-Empirical Modeling of Geosynthetic-Reinforced Unpaved Roads

Abstract

Mechanistic-empirical modeling and design solutions have been routinely used for conventional flexible pavements and have recently entered mainstream design practice through the issue of AASHTO design software. Recent work has been performed to incorporate mechanisms of base reinforcement with geosynthetics into mechanistic-empirical modeling and design. The purpose of this paper is to examine the use of this work for mechanistic-empirical modeling of reinforced unpaved roads by using the same model components used for paved roads and incorporating new components that account for the significant influence of pore-water pressure generation in the subgrade. Results from instrumented unpaved road test sections are used to calibrate and compare with the model predictions. The model provides reasonable predictions of rutting behavior for test sections where rut development is stable, where stable is defined as a rate of rutting that decreases with increasing traffic. The importance of excess pore-water pressure development in the subgrade is illustrated by the test sections and accounted for by the inclusion of steps in the model.