Determining the Optimal Location of Geogrid and Modulus Improvement Factor Using Finite Element Analysis

Reinforcing the conventional flexible pavements constructed on low-strength subgrade soil using different types of geosynthetics improves the performance, service life, and also reduces the maintenance cost. This article demonstrates the significant importance of geogrid’s potential in improving pavement performance. The scope of the work includes investigating optimal location of the geogrid and estimating Modulus Improvement Factor (MIF) as a parameter of pavement layer thicknesses and stiffness of the geogrid. The pavement model is analysed in Finite Element software, and stress-strain and displacement responses were obtained at critical locations. The results highlight the efficacy of the geogrid in diminishing lateral strains in both base and subgrade layers. Furthermore, it reduces the vertical strain and shear strain experienced at the top of the subgrade. The derived MIF matrix, considering different moduli, layer thicknesses, and geogrid stiffness, facilitates the identification of optimal materials and parameters for the efficient and sustainable design of flexible pavements. The MIF obtained in this study ranges from 1.17 to 1.28 for subgrade modulus of 20 MPa by varying the stiffness of the geogrid which is in the desired range as per IRC: SP: 59. The results indicate that the pavement is not only strengthened at various interfaces, but also extends the rutting life. This research makes a significant contribution towards optimizing the application of geogrids in the low volume roads.