Impact of Drainage Geocomposite Affected by Roots on the Infiltration Through a Compacted Soil

Controlling water infiltration through soils has always been one of the major challenges for geotechnical design. In most cases, it is necessary to provide drainage boundary systems, to ensure stability and serviceability to the artefacts involved. The development of new materials and design methods for geotechnical works has been improved considerably over the last years due to recent technological advances. Geosynthetics for filtration and drainage purposes, such as drainage geocomposites (GCD), play a key role in this context, increasingly being used as an alternative to natural resources, which are needed in large quantities to comply with regulation requirements. Therefore, geosynthetics are often seen as a sustainable solution (Dąbrowska et al. in Environments 10(4):64, 1–13, 2023 [1]), as they replace sand and gravel, significantly reducing the thickness of material required for drainage in geotechnical works. Many design solutions imply coexistence between geosynthetics and vegetation throughout the entire service lifetime of the geotechnical work, with the perspective of improving its performance, reducing environmental impact, and preserving ecological corridors. In this respect, the hydraulic performance of the geosynthetics with time, especially when affected by roots (Amato et al. in Geosynth Int, 31(5), 758–772, 2024 [2]), is crucial to the serviceability and maintenance of an earthen structure. Based on previous experimental studies performed on GCD  specimens (Amato et al. in Geosynth Int, 31(5), 758–772, 2024 [2]), this research aims at quantifying some hydraulic effects of the GCD rhizo-disturbance in a boundary value problem. A finite element (FE) analysis was conducted to simulate a rain infiltration process through the backfill of an ideal soil retaining wall, under different conditions for a GCD, either virgin or rooted. Finally, design criteria for geotechnical systems with both GCD and vegetation are proposed.