The internship explores the physics of granular materials reinforced with fibers, a system where the addition of a small fraction of flexible fibers can significantly enhance mechanical strength. While such reinforcement is widely used in engineering and observed in natural root-soil systems, the fundamental mechanisms behind fiber–grain interactions remain poorly understood. The project will involve controlled experiments with grains and synthetic fibers of varying aspect ratios and flexibilities, using setups such as vane rheometry, inclined-plane avalanches, and column collapse. The objective is to identify how parameters like fiber concentration, geometry, and flexibility affect flow behavior and mechanical response, and to contribute to the development of a physical framework and modeling approach that predicts the behavior of fiber-reinforced granular systems across different regimes.