Faced with increasingly demanding maintenance challenges, SNCF Réseau (the French railway infrastructure manager) proposes to use geogrids to improve trackbeds during renovations on its conventional rail lines (speed limit ≤ 220 km/h). This communication presents the design and deployment of a large scale physical model, which reasonably simulates the trackbeds usually found under conventional SNCF rail lines. Cyclic loading is applied, at similar amplitudes to those produced by a train on the field. Measurements (including surface settlement, induced soil pressure, soil-geosynthetic interface settlement…) are used to assess the impact of various geogrids on trackbed performance, mainly characterized by a light falling deflectometer test modulus and the settlement rate during the cyclic loading process.