Three-Dimensional Numerical Analysis of a Geosynthetic-Reinforced Inclusion-Supported Granular Platform under Seismic Response: Validation on Centrifuge Test

Geosynthetic-reinforced inclusion-supported embankments are increasingly adopted for infrastructure projects on soft soils due to their ability to minimize settlement and accelerate construction. This study employs a three-dimensional finite element method (3D FEM) using PLAXIS 3D to investigate the behavior of such embankments under static and cyclic loading, validated against centrifuge test data. The analysis focuses on vertical stress distribution, geosynthetic deflection, and load transfer efficiency, considering key parameters: embankment height (1.0-5.0 m), inclusion modulus (80 MPa - 21 GPa), geosynthetic stiffness (1000-8000 kN/m), and cyclic loading (5 and 50 cycles). Results show that higher embankment heights enhance load transfer efficiency through improved soil arching, reaching 100% at 0.2 m tray movement for a 5.0 m height. Stiffer inclusions (21 GPa) reduce geosynthetic deflection compared to 80 MPa, improving load transfer. Increased geosynthetic stiffness (8000 kN/m) reduces deflection and achieves 100% efficiency at 0.15 m tray movement, enhancing stability via the tensioned membrane effect. Cyclic loading reduces load transfer efficiency by up to 60% compared to static loading, with deflections increasing by 7-11% for 5 and 50 cycles, respectively, due to reduced tensile force mobilization. These findings underscore the importance of optimizing embankment height, inclusion, and geosynthetic stiffness for enhanced stability, particularly under seismic conditions. The validated 3D FEM model provides a robust tool for designing geosynthetic-reinforced embankments, offering critical insights into load transfer mechanisms and seismic performance for soft soil applications.