Large-scale test on basal steel-reinforced piled embankments

This paper presents a novel large-scale test setup at TU Darmstadt to investigate the behaviour of basal reinforced piled embankments. The study focuses on the impact of welded steel mesh reinforcement. The study addresses key questions related to soil arching, deformations, strain distribution in the embankment and the steel mesh grid. The largescale test setup, 25 m², at a 1:1.6 scale, includes 16 piles, a dry medium coarse river sand fill, a steel mesh reinforcement and a two-step system to model the soft soil compaction. State-of-the-art Distributed Fibre Optic Sensing (DFOS) technology enabled precise monitoring of soil and reinforcement strain and 3D deformation. Results indicate that the reinforcement stiffness minimally affects soil arching, matching the Concentric Arches (CA) model (van Eekelen et al., 2013, 2015) that was developed for geosynthetic reinforced piled embankments (GRPS). The deformation pattern and strain distribution in the steel differ from GRPS, illustrating the need for a specific load-deflection model. The measured critical height matches the prediction of Topolnicki and Kłosiński et al. (2022). The study contributes to understanding the complex interaction between steel reinforcement and soft soil in piled embankments, guiding future design considerations.