This paper presents the results of numerical modelling of geosynthetic tubes filled with granular material. In the present study, a numerical model coupling discrete and finite elements was used to describe the behaviour of the encapsulated granular media using clusters and the behaviour of the geosynthetic membrane using finite elements. Initially, a simple compressive loading was applied to the geosynthetic tube to establish the influence of the main parameters governing the mechanical behaviour of the tube. Next, a more complex behaviour was studied by considering an additional lateral action imposed by the backfill of the structure, showing that the influence of the backfill cannot be neglected in the analysis. In the third part of the numerical modelling, a bending test was performed to study the behaviour of the tube in the environment of localised sinkholes. The numerical results were validated by comparison with analytical formulations and were supported by the experimental results described in each section of the analysis. The obtained results and comparisons were reasonably good and a discussion of all the results completes the paper.

A new type of mechanically stabilised earth structure composed of geosynthetic tubes filled with expanded clay lightweight aggregate and backfill with geosynthetic reinforcement is introduced. The results of the study demonstrate that alternative solutions such as expanded clay lightweight aggregates can be used in interaction with geosynthetics in comparison to classical soil. The new type of geosynthetic tubes filled dynamically with expanded clay lightweight aggregate was tested in situ under compressive loading. The geosynthetic tube was instrumented with load cell transducers and the characteristic cross-section was obtained from three-dimensional scanner measurements after loading. Next, a simplified engineering formulation for geosynthetic tubes under compressive loading and unloading was evaluated including the influence of volume variation of the tube. It is based on the classical approach from soil mechanics and it produces the required design tensile force of the tube dependent on geosynthetic stiffness. The experimental results of compressive loading tests were compared with analytical equations. The results are discussed and show the influence of the geosynthetic stiffness on the behaviour of the tube in terms of loading capacity, volume variation and cross-section of the tube. The agreement between theoretical analyses and experimental results was reasonably good and can be formally accepted for a given volume variation of the geosynthetic tube.