3D modelling of gas injection tests on FEBEX material: incorporating heterogeneity effects

An experimental programme was conducted as part of the EURAD-GAS project, with the objective of understanding the mechanisms controlling advective gas flow through the Spanish reference barrier material, FEBEX bentonite. The experimental procedure began with the saturation of the material and was fo...

Descripción completa

Detalles Bibliográficos
Autores: Toprak, Erdem|||0000-0001-9006-3504, Olivella Pastallé, Sebastià|||0000-0003-3976-4027, Gutiérrez Rodrigo, Vanesa, Luis Martín, Pedro, Victoria Villar, María
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/454446
Acceso en línea:https://hdl.handle.net/2117/454446
https://dx.doi.org/10.1680/jenge.24.00180
Access Level:acceso abierto
Palabra clave:3D HM-G modelling
CODE_BRIGHT
FEBEX
Flow characteristics
Heterostructures
Laboratory
Numerical modelling
Radioactive waste disposal
Successive gas BT tests
Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia
Descripción
Sumario:An experimental programme was conducted as part of the EURAD-GAS project, with the objective of understanding the mechanisms controlling advective gas flow through the Spanish reference barrier material, FEBEX bentonite. The experimental procedure began with the saturation of the material and was followed by a series of gas breakthrough (BT) tests. This paper presents a coupled hydro-mechanical and gas transport (HM-G) model to simulate micro- aperture-driven gas flow through FEBEX bentonite. The modelling framework has been refined using an advanced HM model, incorporating strain-dependent permeability for preferential flow pathways. The parameters of the HM-G model were calibrated through the simulation of laboratory-scale experiments and subsequent back-calculations. The model successfully reproduced the results of gas BT tests, encompassing the processes of saturation, gas injection, gas drainage, re-saturation, and subsequent gas injection. The Barcelona Basic Model was employed as the geo-mechanical model to simulate the development of swelling pressure during the hydration process. The model incorporates randomly distributed permeability zones and heterogeneity in dry density. Key findings from this investigation include the successful simulation of successive gas BT processes that correspond to repository-like conditions, considering a three-dimensional model configuration under an elasto-plastic regime.