New challenges in experimental unsaturated soil mechanics. Experimental upscaling of an engineered gas-permeable seal

An example of upscaling phenomena with experimental techniques is presented and discussed within an engineered seal concept for a future deep geological repository for low and intermediate radioactive waste mainly produced by the energy/medicine/industry sectors. The seal will undergo a longterm sat...

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Detalles Bibliográficos
Autores: Romero Morales, Enrique Edgar|||0000-0002-4105-8941, Lloret Morancho, Antonio|||0000-0001-7991-8487, Alvarado Díaz, Clara Elena
Tipo de recurso: artículo
Fecha de publicación:2023
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:2117/404511
Acceso en línea:https://hdl.handle.net/2117/404511
https://dx.doi.org/10.1051/e3sconf/202338205001
Access Level:acceso abierto
Palabra clave:Soil mechanics
Unsaturated soils
Experimental investigation
Gas -- Transportation
Mecànica dels sòls
Gas -- Transport
Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia::Mecànica de sòls
Descripción
Sumario:An example of upscaling phenomena with experimental techniques is presented and discussed within an engineered seal concept for a future deep geological repository for low and intermediate radioactive waste mainly produced by the energy/medicine/industry sectors. The seal will undergo a longterm saturation stage and subsequent gas transport through such a barrier. Consequently, gas entrapment and generation processes (dominated by the degradation of organic substances and metals) are expected to occur in the emplacement caverns along the pollutant waste storage. The case concerns a compacted 80/20 (dry mass) sand/bentonite S/B mixture with a complex microstructure that significantly evolves on hydration affecting the gas transport properties. This type of seal limits the gas pressure by increasing its gas transport capacity (gas-permeable seal). The large-scale and demonstration experiment GAST (Nagra’s GTS, Switzerland) focuses on the S/B response to saturation and the gas transport capacity in the later gas invasion phase. A series of laboratory experiments running parallel to the in situ test and bridging different scales (from bentonite inter-sand filling microstructural tests and point tests to dm-scale mock-ups) are discussed within the saturation, gas breakthrough pressure and gas dissipation process of the gas-permeable seal context.