The long-term field experiment of geogrid-stabilization in ballasted trackbed

The benefits of geogrid stabilization in confining lateral movement of the trackbed and reducing settlement accumulation have been widely demonstrated through laboratory tests. However, the actual stabilization mechanism and long-term performance of geogrid under complex geological conditions remain unclear. In this study, a total of 400 meters of triaxial geogrid was installed in two ballasted railway sections (embankment and cutting), incorporating with ballast replacement operation. Dynamic comparative tests and 500-days long-term monitoring were conducted. Multiple important issues had been considered for evaluating the effectiveness and limitations of geogrid. The results indicate that geogrid provided lateral confinement by forming progressive interlocking with ballast particles, thereby mitigating structural dynamic responses and reducing settlement development. The long-term performance of the geogrid was mainly influenced by loading cycles, tamping interference, and sustained precipitation. These findings can support the widespread field application of geogrid and provide a reference for guiding maintenance operations.