A new double-porosity macroscopic model of bentonite free swelling
A macroscopic model based on a double-porosity approach is proposed to simulate the swelling caused by the subdivision of particles and aggregates that occurs when bentonites are hydrated under a high water content and low confinement. In the model, it is assumed that although the water that occupie...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2022 |
| 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:2117/379850 |
| Acceso en línea: | https://hdl.handle.net/2117/379850 https://dx.doi.org/10.1016/j.enggeo.2022.106725 |
| Access Level: | acceso abierto |
| Palabra clave: | Bentonite deposits Double porosity Macroscopic model Free swelling Macrostructural swelling water Bentonita -- Propietats mecàniques Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia::Mecànica de sòls Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament dels residus |
| Sumario: | A macroscopic model based on a double-porosity approach is proposed to simulate the swelling caused by the subdivision of particles and aggregates that occurs when bentonites are hydrated under a high water content and low confinement. In the model, it is assumed that although the water that occupies this new porous structure can be considered mobile (associated with the macrostructure), its contribution to variations in the energy of the system is similar to that caused by the immobile water that occupies the microstructure. Assuming isothermal conditions, a functional relationship between the increase in the void ratio and the decrease in internal energy was defined from the Clausius-Duhem equation. From this functional relationship, a macroscopic constitutive model was derived to determine the macrostructural swelling as a function of the decrease in the microstructural effective stress. The model was applied to simulate both tests with a large void ratio (up to 50) and processes with a notable variation in salinity (from deionized water to 1 M solution), and satisfactory results were obtained in all cases. This study proposes a simple strategy to incorporate the model into the equations generally used to solve hydro-chemical-mechanical boundary problems at the engineering scale and is thus of direct practical interest. |
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