cam a22 4 4500 52900268X CHVBK 20201202091350.0 180926s2018 sz a m 00 0deng d urn:nbn:ch:bel-1580669 urn (SNL)991017736599703976 (SNL)991018071003603976 (NEBIS)011267552 (Sz)1952013-41snl_51 (Sz)vtls001952013 (Sz)001952013 (Sz)991018071003603976 Sz ger rda eng eng fre ger ita 550 23sdnb Dorostkar Omid 1989- (DE-588)1165820803 Verfasser aut Stick-slip dynamics in dry and fluid saturated granular fault gouge investigated by numerical simulations presented by Omid Dorostkar Zurich 2018 xix, 186 Seiten Illustrationen 24 cm Dissertation No. 24977 ETH Zurich, 2018 Literaturverzeichnis application/pdf Mature faults in the earth comprise a granular fault gouge created due to communition and fragmentation of host rock at the core of the damage zone. It is well understood that granular interactions in this fault gouge govern the dynamics of the fault. The stick-slip dynamics in a sheared granular layer in experiments and simulations is understood to simulate similar physical mechanisms that are involved in earthquakes. The dynamics of a sheared granular fault gouge can be strongly affected by its particle properties, shear driving velocity, confining stress, temperature and pore fluid. Fluids are found to play a significant role in fault mechanics, where they can not only alter the physicochemical properties of gouge materials, but also affect the stick-slip dynamics of the fault. Laboratory experiments have been widely used to investigate the underlying physics of granular interactions in fault mechanics, showing the important role of fluids in slip nucleation and failure process. However, experiments lack detailed information at grain scale to understand the role of fluids in stick-slip dynamics. Furthermore, in experiments the different effects of fluids, such as physicochemical and hydro-mechanical are not distinguishable. Numerical simulations at grain scale however allow unraveling such questions. Here, a 3D coupled Computational Fluid Dynamics-Discrete Element Method is used to model stick-slip dynamics in a granular fault system with fluids. First, a dry granular fault gouge is modeled and its dynamics for different particle properties and under different loading configurations is studied. Next, the effect of capillary cohesion at low saturation degrees, where the capillary bridges are in pendular regime, is studied. The results show an increase of recurrence time between slips and an increase in stress drop due to a rearrangement of the particles owing to the presence of rather low cohesive forces between the wet granular particles. This particle rearrangement results in more stable configurations of the granular layer as indicated by an increase in particle coordination number and shear stiffness of the layer during the stick phase. The results for a fluid saturated fault gouge show that slip events are characterized by a higher drop in friction coefficient, in potential energy and thickness of the gouge layer compared to the dry conditions. The drained fluid saturated granular fault gouge shows higher values for pre-seismic potential energy, describing that the fluid leads to more stable configurations of the granular layer illuminated by a higher particle coordination number. The higher potential energy drop is accompanied by a higher release of kinetic energy in fluid saturated granular fault gouge. The spatial correlation of regions with high fluid velocity, particle-fluid interaction and particle kinetic energy during slip show that the mechanisms of particle rearrangement, increase of fluid pressure and particle-fluid interaction forces are strongly coupled phenomena explaining the macroscopic observations. The high dynamic fluid pressure is due to the fast fluid flow during slip caused by particles rearrangements. The high fluid flow in turn introduces high drag forces on particles leading to a high particle kinetic energy. The coupled fluid-particle simulations provide grain-scale information allowing an in-depth understanding of slip instabilities. The observations in this research emphasize the important role that fluid flow and fluid-particle interactions may play in tectonic fault zones and show in particular how DEM models can help understand the hydro-mechanical processes that dictate fault slip. Englischer Text mit englischer, französischer, italienischer und deutscher Zusammenfassung BODENSTANDFESTIGKEIT + GLEITFLÄCHEN + RUTSCHFLÄCHEN (BODENMECHANIK) ger (ETHUDK)000029883 ethudk BRUCHFESTIGKEIT (ELASTOMECHANIK) ger (ETHUDK)000015748 ethudk FORMÄNDERUNG DURCH SCHERUNG (ELASTOMECHANIK) ger (ETHUDK)000015727 ethudk GEOTECHNIK (ANGEWANDTE GEOLOGIE UND GEOPHYSIK) ger (ETHUDK)000019935 ethudk INDUZIERTE SEISMIZITÄT (GEOPHYSIK) ger (ETHUDK)000053787 ethudk KAKIRIT (GEOLOGIE) ger (ETHUDK)000065757 ethudk KOHÄSIONSFESTIGKEIT (ELASTOMECHANIK) ger (ETHUDK)000015737 ethudk NUMERISCHE SIMULATION UND MATHEMATISCHE MODELLRECHNUNG ger (ETHUDK)000013907 ethudk ROCK-FLUID INTERACTION (PETROGRAPHIE) ger (ETHUDK)000050049 ethudk STRESS-STRAIN (GEOLOGIE) ger (ETHUDK)000055533 ethudk VERWERFUNGEN (GEOLOGIE) ger (ETHUDK)000020022 ethudk Hochschulschrift (DE-588)4113937-9 gnd-content Hochschulschrift gnd-content sb 2018/21 550 zh snl-sb xehelv xediss 2020 550 620 snl ehelv u VERWERFUNGEN (GEOLOGIE) ger 551.243.1 nebis E1 u STRESS-STRAIN (GEOLOGIE) ger 551.254,50 nebis E1 u ROCK-FLUID INTERACTION (PETROGRAPHIE) ger 552.17*8 nebis E1 u KAKIRIT (GEOLOGIE) ger 551.254*11 nebis E1 u BRUCHFESTIGKEIT (ELASTOMECHANIK) ger 539.42 nebis E1 u GEOTECHNIK (ANGEWANDTE GEOLOGIE UND GEOPHYSIK) ger 550.8%62 nebis E1 u BODENSTANDFESTIGKEIT + GLEITFLÄCHEN + RUTSCHFLÄCHEN (BODENMECHANIK) ger 624.131.537 nebis E1 u FORMÄNDERUNG DURCH SCHERUNG (ELASTOMECHANIK) ger 539.386 nebis E1 u INDUZIERTE SEISMIZITÄT (GEOPHYSIK) ger 550.348.42,2 nebis E1 u KOHÄSIONSFESTIGKEIT (ELASTOMECHANIK) ger 539.41 nebis E1 u NUMERISCHE SIMULATION UND MATHEMATISCHE MODELLRECHNUNG ger 519.876.5 nebis E1 u FAULT (GEOLOGY) eng 551.243.1 nebis E1 u FAILLE (GÉOLOGIE) fre 551.243.1 nebis E1 u STRESS-STRAIN (GEOLOGY) eng 551.254,50 nebis E1 u STRESS-STRAIN (GÉOLOGIE) fre 551.254,50 nebis E1 u INTERACTION ROCHE-FLUIDE (PÉTROGRAPHIE) fre 552.17*8 nebis E1 u ROCK-FLUID INTERACTION (PETROGRAPHY) eng 552.17*8 nebis E1 u KAKIRIT (GEOLOGY) eng 551.254*11 nebis E1 u KAKIRIT (GÉOLOGIE) fre 551.254*11 nebis E1 u BREAKING STRENGTH (ELASTOMECHANICS) eng 539.42 nebis E1 u RÉSISTANCE À LA RUPTURE (MÉCANIQUE DES CORPS ÉLASTIQUES) fre 539.42 nebis E1 u ENGINEERING GEOLOGY (APPLIED GEOLOGY AND GEOPHYSICS) eng 550.8%62 nebis E1 u GÉOTECHNIQUE (GÉOLOGIE ET GÉOPHYSIQUE APPLIQUÉE) fre 550.8%62 nebis E1 u STABILITÉ DU SOL + SURFACES DE GLISSEMENT (MÉCANIQUE DES SOLS) fre 624.131.537 nebis E1 u SOIL STABILITY + SLIDE SURFACES + SLIP SURFACES (SOIL MECHANICS) eng 624.131.537 nebis E1 u DEFORMATION BY SHEARING (ELASTOMECHANICS) eng 539.386 nebis E1 u DÉFORMATION PAR CISAILLEMENT (MÉCANIQUE DES CORPS ÉLASTIQUES) fre 539.386 nebis E1 u INDUCED SEISMICITY (GEOPHYSICS) eng 550.348.42,2 nebis E1 u SÉISMICITÉ INDUITE (GÉOPHYSIQUE) fre 550.348.42,2 nebis E1 u STRENGTH AGAINST ELASTIC DEFORMATION (ELASTOMECHANICS) eng 539.41 nebis E1 u FORCE DE COHÉSION (MÉCANIQUE DES CORPS ÉLASTIQUES) fre 539.41 nebis E1 u SIMULATION NUMÉRIQUE ET MODÉLISATION MATHÉMATIQUE fre 519.876.5 nebis E1 u NUMERICAL SIMULATION AND MATHEMATICAL MODELING eng 519.876.5 nebis E1 Eidgenössische Technische Hochschule Zürich (DE-588)2023928-2 Grad-verleihende Institution dgg SNL NB001 NB999 - chb99 - https://opac.admin.ch/toc/toc1902039142.pdf Inhaltsverzeichnis BK020300 XK020000 XK020000 078 E01-20180917 025 E01-20180917 SNL NB001 NB001 Nb 207496 NB10010 NEBIS E16 E16 RH Diss ETH 24977 SNL 100 1- Dorostkar Omid 1989- (DE-588)1165820803 Verfasser aut SNL 856 41 https://opac.admin.ch/toc/toc1902039142.pdf Inhaltsverzeichnis SNL 710 2- Eidgenössische Technische Hochschule Zürich (DE-588)2023928-2 Grad-verleihende Institution dgg SNL 100 1- Dorostkar Omid Verfasser aut SNL 856 40 http://hdl.handle.net/20.500.11850/283977 SNL 856 4- https://nbn-resolving.org/urn:nbn:ch:bel-1580669 SNL 856 42 http://www.e-helvetica.nb.admin.ch/directAccess?callnumber=bel-1580669 NEBIS 100 1- Dorostkar Omid 1989- (DE-588)1165820803 Verfasser aut NEBIS 700 1- Carmeliet Jan 1961- (DE-588)1089485204 Akademischer Betreuer dgs NEBIS 700 1- Bonn Daniel Akademischer Betreuer dgs