Tensile strength of a vegetated and partially saturated soil

Vegetated soil’s shear strength has been usually assessed through direct shear tests and under triaxial compression stress paths while less is known about its behaviour under tensile stress. Tensile strength and shrinkage-induced cracking play a crucial role in the hydro-mechanical response of earth...

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Bibliographic Details
Authors: Fraccica, Alessandro, Romero Morales, Enrique Edgar|||0000-0002-4105-8941, Fourcaud, Thierry, Sondon Sansó, Mercedes, Gandarillas, Luis
Format: article
Publication Date:2020
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/340324
Online Access:https://hdl.handle.net/2117/340324
https://dx.doi.org/10.1051/e3sconf/202019503001
Access Level:Open access
Keyword:Soil mechanics--Testing
Mecànica dels sòls -- Proves
Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia::Mecànica de sòls
Description
Summary:Vegetated soil’s shear strength has been usually assessed through direct shear tests and under triaxial compression stress paths while less is known about its behaviour under tensile stress. Tensile strength and shrinkage-induced cracking play a crucial role in the hydro-mechanical response of earth structures exposed to drying/wetting cycles. For this purpose, a new device for direct tensile tests has been designed and used to let plants grow in compacted soil samples. The equipment consists of two cylindrical moulds connected to each other by a soil bridge in which failure upon pulling is induced due to geometrical constraints. Different soil’s mechanical responses were observed depending on whether suction was low or high. Indeed, it was detected an increase of soil tensile strength and a more brittle behaviour as suction was increasing. However, at the same suction, vegetated soil’s response was more ductile than that of the corresponding bare soil. Results were analysed within a shear strength criterion for partially saturated soils. The analysis evidenced an increase in shear strength in the vegetated soil. A correlation was found between this increase and the roots’ mechanical and morphological features.