The thesis presents numerical and experimental studies on joints.A formulation for the coupled analysis of thermo- hydro- mechanical problems in joints is presented. The work involves the establishment of equilibrium and mass and energy balance equations. Balance equations were formulated taking into account two phases: water and air. Once the joint element was implemented in Code_Bright computer code, it was then used to study some cases. The numerical simulation of hydraulic shear tests of roughness granite joints is presented. This allowed evaluating the coupling between permeability and the geometry of the opening of the joint. Then, a thermo-hydro-mechanical simulation of a large-scale nuclear waste repository was performed considering the joint element to model the interface between canister and bentonite. This example allowed evaluating the behaviour of the joint element when coupled to continuum elements. Then, other examples show how hydro-mechanical coupling affects the permeability and saturation of the joints and adjacent material. Finally, the gas flow through joints was also investigated.The experimental investigation focused on the effects of suction on the mechanical behaviour of rock joints. Laboratory tests were performed in a direct shear cell equipped with suction control. Suction was monitored using a vapour forced convection circuit controlled by an air pump that was connected to the shear cell. Once equilibrium conditions are achieved, the rock specimen is assumed to reach the Relative Humidity imposed by the flowing air at a given vapour concentration. Artificial joints of Lilla claystone were prepared. Joint roughness of varying intensity was created by carving the surfaces in contact in such a manner that rock ridges of different tip angles formed. These angles ranged from 0º (smooth joint) to 45º (very rough joint profile). The geometric profiles of the two surfaces in contact were initially positioned in a "matching" situation. Several tests were performed for different values of suction (200, 100 and 20 MPa) and for different values of vertical stress (30, 60 and 150 kPa).A constitutive model including the effects of suction and joint roughness is proposed to simulate the unsaturated behaviour of rock joints.The new constitutive law was incorporated in the code and experimental data were numerically simulated.
| Identifer | oai:union.ndltd.org:TDX_UPC/oai:www.tdx.cat:10803/6274 |
| Date | 22 November 2010 |
| Creators | Zandarín Iragorre, María Teresa |
| Contributors | Olivella Pastallé, Sebastià, Alonso, Eduardo (Alonso Pérez de Agreda), Universitat Politècnica de Catalunya. Departament d'Enginyeria del Terreny, Cartogràfica i Geofísica |
| Publisher | Universitat Politècnica de Catalunya |
| Source Sets | Universitat Politècnica de Catalunya |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | application/pdf |
| Source | TDX (Tesis Doctorals en Xarxa) |
| Rights | info:eu-repo/semantics/openAccess, ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs. |
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