Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.

Bentonite-based materials are being currently considered in several countries as a backfill component in the multi-barrier concept for deep geological disposal of radioactive waste. The bentonite barrier fulfils several important functions: i) high swelling capacity to fill gaps and compress the exc...

Descripción completa

Detalles Bibliográficos
Autor: Ruiz Restrepo, Daniel Felipe
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/669205
Acceso en línea:http://hdl.handle.net/10803/669205
https://dx.doi.org/10.5821/dissertation-2117-192447
Access Level:acceso abierto
Palabra clave:Àrees temàtiques de la UPC::Enginyeria civil
55
579
624
id ES_df85e6a5cc2ee885abc9e6f2003b4a20
oai_identifier_str oai:www.tdx.cat:10803/669205
network_acronym_str ES
network_name_str España
repository_id_str
spelling Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.Ruiz Restrepo, Daniel FelipeÀrees temàtiques de la UPC::Enginyeria civil55579624Bentonite-based materials are being currently considered in several countries as a backfill component in the multi-barrier concept for deep geological disposal of radioactive waste. The bentonite barrier fulfils several important functions: i) high swelling capacity to fill gaps and compress the excavation damaged zone and ii) very low hydraulic conductivity and important retention capacity which retards significantly radionuclides transport. Small-scale testing in geotechnical laboratories and in-situ experiments in underground research laboratories (URL) have demonstrated that initial state, water supply conditions and volume constrictions are the main aspects affecting the behaviour of bentonites. In this context, the main objective of the present study is the numerical simulation of the hydro-mechanical behaviour of expansive clays. For this purpose, a constitutive model has been developed to characterise the bentonite-based materials. The modelling of these materials is a quite challenging task. They exhibit a marked double-porosity system in which the swelling/shrinkage mechanism occurs at clay aggregate level and the collapsible behaviour comes from granular-like skeleton formed by the aggregates. In addition, several material configuration, with even more intricate fabric, have been proposed for the emplacement works of seals and plugs. The explicit consideration of two structural levels for the constitutive model seems to be suitable. Mechanical interaction and water mass exchanges between them can explain the short- and long-term behaviour. The model has been formulated using concepts of elasto-plasticity for strain hardening materials and generalized plasticity theory. The formulation has been implemented in the finite element code program CODE-BRIGHT and has been used to solve a variety of problems. The results provide relevant insights into the hydro-mechanical behaviour of double structure porous media, and they indicated the main aspects affecting the responses of expansive barriers. In particular, the relevance of the structural levels interaction has been demonstrated.DOCTORAT EN ENGINYERIA DEL TERRENY (Pla 2012)Universitat Politècnica de CatalunyaGens, A. (Antonio)Vaunat, JeanUniversitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental202020202020info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersion307 p.application/pdfapplication/pdfhttp://hdl.handle.net/10803/669205https://dx.doi.org/10.5821/dissertation-2117-192447TDX (Tesis Doctorals en Xarxa)reponame:TDR. Tesis Doctorales en Redinstname:CBUC, CESCAInglésL'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-nd/4.0/http://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessoai:www.tdx.cat:10803/6692052026-06-14T12:46:07Z
dc.title.none.fl_str_mv Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
title Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
spellingShingle Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
Ruiz Restrepo, Daniel Felipe
Àrees temàtiques de la UPC::Enginyeria civil
55
579
624
title_short Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
title_full Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
title_fullStr Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
title_full_unstemmed Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
title_sort Hydro-mechanical analysis of expansive clays : constitutive and numerical modelling.
dc.creator.none.fl_str_mv Ruiz Restrepo, Daniel Felipe
author Ruiz Restrepo, Daniel Felipe
author_facet Ruiz Restrepo, Daniel Felipe
author_role author
dc.contributor.none.fl_str_mv Gens, A. (Antonio)
Vaunat, Jean
Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental
dc.subject.none.fl_str_mv Àrees temàtiques de la UPC::Enginyeria civil
55
579
624
topic Àrees temàtiques de la UPC::Enginyeria civil
55
579
624
description Bentonite-based materials are being currently considered in several countries as a backfill component in the multi-barrier concept for deep geological disposal of radioactive waste. The bentonite barrier fulfils several important functions: i) high swelling capacity to fill gaps and compress the excavation damaged zone and ii) very low hydraulic conductivity and important retention capacity which retards significantly radionuclides transport. Small-scale testing in geotechnical laboratories and in-situ experiments in underground research laboratories (URL) have demonstrated that initial state, water supply conditions and volume constrictions are the main aspects affecting the behaviour of bentonites. In this context, the main objective of the present study is the numerical simulation of the hydro-mechanical behaviour of expansive clays. For this purpose, a constitutive model has been developed to characterise the bentonite-based materials. The modelling of these materials is a quite challenging task. They exhibit a marked double-porosity system in which the swelling/shrinkage mechanism occurs at clay aggregate level and the collapsible behaviour comes from granular-like skeleton formed by the aggregates. In addition, several material configuration, with even more intricate fabric, have been proposed for the emplacement works of seals and plugs. The explicit consideration of two structural levels for the constitutive model seems to be suitable. Mechanical interaction and water mass exchanges between them can explain the short- and long-term behaviour. The model has been formulated using concepts of elasto-plasticity for strain hardening materials and generalized plasticity theory. The formulation has been implemented in the finite element code program CODE-BRIGHT and has been used to solve a variety of problems. The results provide relevant insights into the hydro-mechanical behaviour of double structure porous media, and they indicated the main aspects affecting the responses of expansive barriers. In particular, the relevance of the structural levels interaction has been demonstrated.
publishDate 2020
dc.date.none.fl_str_mv 2020
2020
2020
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
info:eu-repo/semantics/publishedVersion
format doctoralThesis
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10803/669205
https://dx.doi.org/10.5821/dissertation-2117-192447
url http://hdl.handle.net/10803/669205
https://dx.doi.org/10.5821/dissertation-2117-192447
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv http://creativecommons.org/licenses/by-nc-nd/4.0/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-nd/4.0/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 307 p.
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Universitat Politècnica de Catalunya
publisher.none.fl_str_mv Universitat Politècnica de Catalunya
dc.source.none.fl_str_mv TDX (Tesis Doctorals en Xarxa)
reponame:TDR. Tesis Doctorales en Red
instname:CBUC, CESCA
instname_str CBUC, CESCA
reponame_str TDR. Tesis Doctorales en Red
collection TDR. Tesis Doctorales en Red
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869422071490019328
score 15,300724

Similares en LA Referencia