Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.jrmge.2022.05.011
Licence creative commons licence
Title (Primary) Simulation of dilatancy-controlled gas migration processes in saturated bentonite using a coupled multiphase flow and elastoplastic H2M model
Author Radeisen, E.; Shao, H.; Hesser, J.; Kolditz, O. ORCID logo ; Xu, W.; Wang, W.Q. ORCID logo
Source Titel Journal of Rock Mechanics and Geotechnical Engineering
Year 2023
Department ENVINF
Volume 15
Issue 4
Page From 803
Page To 813
Language englisch
Topic T8 Georesources
Keywords H2M coupling; Gas migration; Dilatancy-controlled flow; Continuous approach; Geomaterial heterogeneity; OpenGeoSys
Abstract Dilatancy-controlled gas flow in preferential pathways plays a key role in the safety analysis of radioactive waste repositories. This is particularly the case for bentonite, an often-preferred barrier material. Gas flow in preferential pathways is characterized by localization and spontaneous behavior, which is challenging to simulate in numerical models due to strong hydro-mechanical coupling. To analyze a laboratory experiment in the framework of the DECOVALEX-2023 project, this study introduced a new approach of combining continuous modelling methods with spatial material properties derived from material heterogeneities and experimental observations. The proposed model utilized hydro-mechanical spatial distributions, namely Young's modulus and gas entry pressure, and elastoplasticity combined with a linear swelling model. A conceptual strain-dependent permeability approach simulated dilatancy-controlled gas flow based on hydro-mechanical coupling. To test the effectiveness of the presented approach, a gas injection test in a compacted, saturated bentonite sample was simulated using the open-source code OpenGeoSys 5.8 and compared with experimental observations. The presented methodology is capable of simulating localized gas flow in preferential pathways. The spatial distributions of Young's modulus and gas entry pressure affect the swelling pressure, relative permeability and, in combination with the strain-dependent permeability model, also the intrinsic permeability.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=26298
Radeisen, E., Shao, H., Hesser, J., Kolditz, O., Xu, W., Wang, W.Q. (2023):
Simulation of dilatancy-controlled gas migration processes in saturated bentonite using a coupled multiphase flow and elastoplastic H2M model
J. Rock Mech. Geotech. Eng. 15 (4), 803 - 813 10.1016/j.jrmge.2022.05.011