3D Numerical Analysis of a Geogrid-Reinforced Piled Embankment: High-Speed Railway

Abstract

A full-scale experimental geosynthetic-reinforced piled embankment (GRPE) and its numerical back analysis are presented in this article. The site is in Virvée (France) and is part of the new South Europe Atlantic high-speed line project. A GRPE system using geosynthetics with high tensile stiffness (≥10,000 kN/m) was proposed as an optimized solution to replace a classical pile-supported embankment (PE). Based on full-scale tests, three-dimensional finite-element models are considered to simulate both GRPE and PE solutions. The numerical results obtained are presented in comparison with in situ measurements. Settlements, pile stresses, and the geosynthetic strains are investigated. Then, a parametric study was conducted for the GRPE system to evaluate the influences of pile net spacing, geogrid tensile stiffness, and different numbers of high to relatively low tensile stiffness geosynthetic layers on the load transfer performance. The results show that the geosynthetic number of layers has less impact for the high tensile stiffness cases on the system settlement and load transfer efficiency. The use of a double-layer geosynthetic reinforcement with high tensile stiffness enhances the overall performance of the geosynthetic-reinforced piled embankment.