Modelling gas fracturing in saturated clay samples using triple-node zero-thickness interface elements

Modelling gas fracturing in saturated clay samples using triple-node zero-thickness interface elements

Liaudat, J. (TU Delft Geo-engineering)
Dieudonné, A.A.M. (TU Delft Geo-engineering)
Vardon, P.J. (TU Delft Geo-engineering)

2023

Geological Disposal Facilities (GDF) for radioactive waste will generally rely on clay-rich materials as a host geological formation and/or engineered barrier. Gas will be produced within the GDF, which can build up significant gas pressure and will activate the migration of gas through the clay materials via different transport mechanisms. These transport mechanisms are usually investigated in laboratory tests on small clay samples of a few centimetres. In this paper, a new Pneumo-Hydro-Mechanical (PHM) Finite Element model to simulate gas migration in saturated clay samples of this scale is presented. In the proposed modelling approach, continuum elements are used to represent the mechanical and flow processes in the bulk clay material, while zero-thickness interface elements are used to represent existing or induced discontinuities (cracks). A new triple-node PHM interface element is presented to achieve this. The performance of model is illustrated with synthetic benchmark examples which show the ability of the model to reproduce observed PHM mechanisms leading to propagation of cracks due to the gas pressure (gas fracturing).

Clay
Finite Element Method
Gas fracturing
Gas migration
Interface elements
Two-phase flow

http://resolver.tudelft.nl/uuid:9127e6dc-c048-4a9f-8e1e-7fe1f979a3a7

https://doi.org/10.1016/j.compgeo.2022.105128

0266-352X

Computers and Geotechnics, 154

Institutional Repository

journal article

© 2023 J. Liaudat, A.A.M. Dieudonné, P.J. Vardon