Analytical Model for Resilient Modulus and Permanent Deformation of Geosynthetic-Reinforced Unbound Granular Material

Abstract

To consider the benefit of geosynthetic reinforcement in a mechanistic-empirical pavement design method, the resilient modulus and permanent deformation behavior of a geosynthetic-reinforced unbound granular material (UGM) must be considered. Many researchers conducted repeated-load triaxial (RLT) tests to investigate the resilient and permanent deformation behavior of the geosynthetic-reinforced UGM. However, these tests are difficult to perform, and the results are often interpreted empirically. Thus, implementation of the research results is limited. In this study, an analytical model was developed to predict the resilient modulus and permanent deformation of the geosynthetic-reinforced UGM in RLT tests. The analytical model is compatible with the resilient modulus and permanent deformation models in the current mechanistic-empirical pavement design guide. Both planar and three-dimensional geosynthetics can be analyzed using this model. RLT test results from two published studies were selected to validate the proposed analytical model. In general, the analytical results confirmed and explained the typical test observations from previous studies that geosynthetic reinforcement is more effective in reducing the permanent deformation than increasing the resilient modulus of the UGM sample. A parametric analysis was conducted to investigate the effect of input parameters (i.e., material properties, sample dimensions, and stress level) on the analytical model. The limitations, assumption, and implementation of the model are also discussed.