Large cell triaxial tests of a partially saturated soil with vegetation - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Conference Papers Year : 2023

Large cell triaxial tests of a partially saturated soil with vegetation


The use of vegetation roots as a nature-based solution against landslides and erosion requires the definition of sample preparation protocols and adoption of equipment that allows testing representative elementary volumes of the whole soil-root system. For this purpose, large cell triaxial compression tests were carried out on fallow and vegetated samples at different degrees of saturation. Samples were prepared by static compaction of a silty sand and seeded with Cynodon dactylon. The hydraulic state during plants growth was controlled and reproduced on bare soil samples. After isotropic compressions, the shearing phase was carried out at very low confining stresses (i.e., below 50 kPa). Tests were deemed to be comparable by assessing the normalised volume of roots with respect to soil, after shearing. For a given confining stress, soil samples with higher matric suction exhibited higher shear strength, furtherly increased by roots. The stress-strain behaviour observed in the vegetated soil systematically changed, when comparing tests at low and high matric suction values, due to the different mechanisms of vegetation reinforcement depending on the hydraulic state at the soil-root interface. The results were successfully interpreted within a failure criterion and skeleton stress framework for partially saturated soils, considering soil suction, degree of saturation, soil microstructure and the normalised volume of roots.
Fichier principal
Vignette du fichier
e3sconf_unsat2023_05005.pdf (3.45 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Licence : CC BY - Attribution

Dates and versions

hal-04086568 , version 1 (02-05-2023)



Alessandro Fraccica, Enrique Romero, Thierry Fourcaud. Large cell triaxial tests of a partially saturated soil with vegetation. 8th International Conference on Unsaturated Soils (UNSAT 2023), International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE), May 2023, Milos Island, Greece. pp.05005, ⟨10.1051/e3sconf/202338205005⟩. ⟨hal-04086568⟩
19 View
3 Download



Gmail Facebook Twitter LinkedIn More