Journal ArticleComputer Methods in Applied Mechanics and Engineering · May 1, 2024
This paper presents an extension of the discrete element method using a phase-field formulation to incorporate grain shape and its evolution. The introduction of a phase variable enables an effective representation of grain geometry and facilitates the app ...
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Journal ArticleGeomechanics for Energy and the Environment · December 1, 2023
This manuscript is Part 1 of two companion papers that explore a multidisciplinary approach to predict velocity and stability of a large landslide located in the Central Italian Alps: the Ruinon landslide. The area is of high geological interest due to the ...
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Chapter · January 1, 2023
Under compression, rate-dependent solids subject to hydro-mechanical processes have been shown to accommodate singular cnoidal wave solutions [1], as a material instability at the stationary wave limit. Given the numerical complexity to solve the correspon ...
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Journal ArticleGeomechanics for Energy and the Environment · June 1, 2021
Velocity stepping experiments have been performed on a simulated calcite gouge using an annular shear apparatus to investigate the effect of dissolution on the frictional properties of a carbonate fault. The tested material was put in contact with hydrochl ...
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Journal ArticleGeomechanics for Energy and the Environment · March 1, 2021
In this note we present a theoretical study on the conditions for the onset of cracks, as well as the corresponding pattern formation, in saturated viscoplastic soils under isotropic loading (extension). The type of stress applied is left unspecified, to c ...
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Journal ArticleComputer Methods in Applied Mechanics and Engineering · June 15, 2020
Fluid injection or production in petroleum reservoirs affects the reservoir stresses such that it can even sometime reactivate dormant faults in the vicinity. In the particular case of deep carbonate reservoirs, faults can also be chemically active and che ...
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Journal ArticleGeomechanics for Energy and the Environment · May 1, 2020
As energy operations face the challenge of reservoirs at ever-increasing depths, modelling the response of reservoir rocks at high pressure and high temperature (HPHT) conditions is a crucial step for successfully unlocking new resources. At these conditio ...
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Journal ArticleComputers and Geotechnics · January 1, 2020
As multiphysics geomechanical models get developed, their increasing complexity and number of parameters make it particularly difficult to calibrate against experimental data. In this contribution, we present a heuristic workflow to invert for parameters o ...
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Journal ArticleNature communications · January 2020
The triggering and magnitude of earthquakes is determined by the friction evolution along faults. Experimental results have revealed a drastic decrease of the friction coefficient for velocities close to the maximum seismic one, independently of the materi ...
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Journal ArticleComputer Methods in Applied Mechanics and Engineering · May 1, 2024
This paper presents an extension of the discrete element method using a phase-field formulation to incorporate grain shape and its evolution. The introduction of a phase variable enables an effective representation of grain geometry and facilitates the app ...
Full textCite
Journal ArticleGeomechanics for Energy and the Environment · December 1, 2023
This manuscript is Part 1 of two companion papers that explore a multidisciplinary approach to predict velocity and stability of a large landslide located in the Central Italian Alps: the Ruinon landslide. The area is of high geological interest due to the ...
Full textCite
Chapter · January 1, 2023
Under compression, rate-dependent solids subject to hydro-mechanical processes have been shown to accommodate singular cnoidal wave solutions [1], as a material instability at the stationary wave limit. Given the numerical complexity to solve the correspon ...
Full textCite
Journal ArticleGeomechanics for Energy and the Environment · June 1, 2021
Velocity stepping experiments have been performed on a simulated calcite gouge using an annular shear apparatus to investigate the effect of dissolution on the frictional properties of a carbonate fault. The tested material was put in contact with hydrochl ...
Full textCite
Journal ArticleGeomechanics for Energy and the Environment · March 1, 2021
In this note we present a theoretical study on the conditions for the onset of cracks, as well as the corresponding pattern formation, in saturated viscoplastic soils under isotropic loading (extension). The type of stress applied is left unspecified, to c ...
Full textCite
Journal ArticleComputer Methods in Applied Mechanics and Engineering · June 15, 2020
Fluid injection or production in petroleum reservoirs affects the reservoir stresses such that it can even sometime reactivate dormant faults in the vicinity. In the particular case of deep carbonate reservoirs, faults can also be chemically active and che ...
Full textCite
Journal ArticleGeomechanics for Energy and the Environment · May 1, 2020
As energy operations face the challenge of reservoirs at ever-increasing depths, modelling the response of reservoir rocks at high pressure and high temperature (HPHT) conditions is a crucial step for successfully unlocking new resources. At these conditio ...
Full textCite
Journal ArticleComputers and Geotechnics · January 1, 2020
As multiphysics geomechanical models get developed, their increasing complexity and number of parameters make it particularly difficult to calibrate against experimental data. In this contribution, we present a heuristic workflow to invert for parameters o ...
Full textCite
Journal ArticleNature communications · January 2020
The triggering and magnitude of earthquakes is determined by the friction evolution along faults. Experimental results have revealed a drastic decrease of the friction coefficient for velocities close to the maximum seismic one, independently of the materi ...
Full textCite
Journal ArticleTectonophysics · October 30, 2018
Here we used a physics-based geomechanics approach to show that the long-term strength of the lithosphere is controlled by multiple steady states that arise as a function of significant material weakening at and above a critical value of local dissipation. ...
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Journal ArticleTectonophysics · October 30, 2018
Incorporating coupled Thermal-Hydro-Mechanical-Chemical (THMC) processes in lithospheric deformation models is a research frontier in the study of lithosphere dynamics. In this study we present a fundamental theoretical analysis on the important lithospher ...
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Journal ArticleRock Mechanics and Rock Engineering · October 1, 2018
A numerical model for thermo-hydro-mechanical strong couplings in an elasto-plastic Cosserat continuum is developed to explore the influence of frictional heating and thermal pore fluid pressurization on the strain localization phenomenon. This model allow ...
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Journal ArticleJournal of the Mechanics and Physics of Solids · June 1, 2018
In this paper we study the phenomenon of localization of deformation in fault gouges during seismic slip. This process is of key importance to understand frictional heating and energy budget during an earthquake. A infinite layer of fault gouge is modeled ...
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Journal ArticleGeophysical Journal International · January 1, 2018
Quantifying rock physical properties is essential for the mining and petroleum industry. Microtomography provides a new way to quantify the relationship between the microstructure and the mechanical and transport properties of a rock. Studies reporting the ...
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ConferenceSociety of Petroleum Engineers - SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition 2018, SATS 2018 · January 1, 2018
It is not uncommon that wells drilled in shale reservoirs experience a large Initial Production (IP), followed by a significant drop in productivity a few months after hydraulic fracturing, leading to a reduced Estimated Ultimate Recovery (EUR), with prima ...
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Journal ArticleGeomechanics for Energy and the Environment · December 1, 2017
Flow simulators have become increasingly popular to compute permeability on digital porous rocks reconstructed from Computerised Tomography (CT) scan data as part of Digital Rock Physics workflows. Various schemes are being used that focus mainly on numeri ...
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Journal ArticleRock Mechanics and Rock Engineering · November 1, 2017
This paper investigates localized shear deformation around a borehole due to internal pressure in the well such as by fluid injection. Using an elasto-visco-plastic formulation combined with damage mechanics for the effect of shear cracking, we first bench ...
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Journal ArticleScientific reports · October 2017
Nature has a range of distinct mechanisms that cause initially heterogeneous systems to break their symmetry and form patterns. One of these patterns is zebra dolomite that is frequently hosting economically important base metal mineralization. A consisten ...
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Journal ArticleRock Mechanics and Rock Engineering · March 1, 2017
Understanding the formation, geometry and fluid connectivity of nominally impermeable unconventional shale gas and oil reservoirs is crucial for safe unlocking of these vast energy resources. We present a recent discovery of volumetric instabilities of duc ...
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Journal ArticleRock Mechanics and Rock Engineering · March 1, 2017
Faults play a major role in many economically and environmentally important geological systems, ranging from impermeable seals in petroleum reservoirs to fluid pathways in ore-forming hydrothermal systems. Their behavior is therefore widely studied and fau ...
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Journal ArticlePhysics of the Earth and Planetary Interiors · March 1, 2017
Episodic Tremor and Slip (ETS) events display a rich behaviour of slow and accelerated slip with simple oscillatory to complicated chaotic time series. It is commonly believed that the fast events appearing as non volcanic tremors are signatures of deep fl ...
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Chapter · January 1, 2017
In this paper, we show the impact of Thermo-Hydro Mechanical couplings (THM) on the stability of a saturated fault gouge under shear. By resorting to Cosserat continuum mechanics, that allows to take into account rotational degrees of freedom, we regulariz ...
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Chapter · January 1, 2017
Compaction bands are localized failure patterns that appear in highly porous rock material under the effect of relatively high confining pressure. Being affected mainly by volumetric compression, these bands appear to be almost perpendicular to the most co ...
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Chapter · January 1, 2017
A Finite Element implementation is presented to solve for Stokes flow on a deformable rock matrix reconstituted from a stack of computerized tomography images. Tightly coupling this flow solution with a mechanical deformation model exhibits the hydro-mecha ...
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Chapter · January 1, 2017
In this work we present an inversion framework to identify material properties defining the plastic behaviour of pore collapse modeled by thermo-hydro-mechanical simulations. This framework is built on the finite element REDBACK numerical simulator, which ...
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Chapter · January 1, 2017
This paper presents a novel method to investigate shear stimulation at an injection well in Enhanced Geothermal Systems (EGS). Nowadays, the technique of EGS has been extensively used for extracting thermal energy from the earth. As the intrinsic permeabil ...
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Chapter · January 1, 2017
The study of bifurcation criteria for non-isothermal processes in geomaterials requires approaches that deviate from the classical material bifurcation approach. Indeed, in a quasi-static stress state of the medium, the admissible equilibria are of steady- ...
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Journal ArticleGeophysical Journal International · January 1, 2017
The interaction between mechanical deformation of creeping faults and fluid flow in porous media has an important influence on the heat and mass transfer processes in Earth sciences. Creeping faults can act as heat sources due to the effect of shear heatin ...
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Journal ArticleEnergy and Fuels · December 15, 2016
Total rock porosity is a key parameter in a wide range of disciplines from petroleum to civil and mining engineering. Porosity is particularly important in petroleum engineering applications, e.g., from estimation of hydrocarbon in place to prediction of g ...
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Journal ArticleMathematics · December 1, 2016
Instabilities in Geomechanics appear on multiple scales involving multiple physical processes. They appear often as planar features of localised deformation (faults), which can be relatively stable creep or display rich dynamics, sometimes culminating in e ...
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Journal ArticleInternational Journal of Engineering Science · October 1, 2016
Traditional slip-line field theory considers steady-state pressure distributions. This work examines the evolution of pressure at yield. We show that, for a two phase material in plane strain at the point of plastic yield of the main constituent, pressure ...
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Journal ArticleJournal of Geophysical Research: Solid Earth · May 1, 2016
We present a theory for the onset of localization in layered rate- and temperature-sensitive rocks, in which energy-related mechanical bifurcations lead to localized dissipation patterns in the transient deformation regime. The implementation of the couple ...
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Journal ArticleComputers and Geotechnics · April 1, 2016
Numerical simulators have become indispensable in geomechanics to model increasingly more complex rock behaviours by harnessing the growing computational power available. Those tools aim at simulating more realistic scenarios while accounting for more phys ...
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Journal ArticleJournal of Mechanics of Materials and Structures · January 1, 2016
We study the onset of localisation of plastic deformation for a class of materials that exhibit both temperature and rate sensitivity. The onset of localisation is determined via an energy bifurcation criterion, defined by the postulate that viscoplastic m ...
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Journal ArticleLeading Edge · January 1, 2016
A novel wave-mechanics approach is developed specifically for understanding instabilities that form large natural fluidtransmissivity networks in unconventional reservoirs located in a nominally impermeable matrix. Thse natural flow networks are trapped in ...
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Journal ArticlePhilosophical Magazine · October 23, 2015
We propose a new multi-physics, multi-scale Integrated Computational Materials Engineering framework for predictive geodynamic simulations. A first multiscale application is presented that allows linking our existing advanced material characterization meth ...
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Journal ArticleJournal of Structural Geology · September 1, 2015
Pinch-and-swell structures are commonly interpreted to evolve out of viscosity contrasts, which are induced by geometric interactions and material imperfections. From materials science an additional localization phenomenon is well established, where locali ...
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Journal ArticleGeology · April 24, 2015
A common and puzzling feature of migmatite terranes is the presence of synkinematic leucosomes oriented perpendicular to the maximum principal compressive stress axis, σ1, particularly leucosomes oriented parallel to the axial plane of folds. These are par ...
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Journal ArticleJournal of Earth Science · February 1, 2015
Deep geothermal from the hot crystalline basement has remained an unsolved frontier for the geothermal industry for the past 30 years. This poses the challenge for developing a new unconventional geomechanics approach to stimulate such reservoirs. While a ...
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Journal ArticleCurrent Opinion in Chemical Engineering · January 1, 2015
Variational principles applied to the time derivative of the second law of thermodynamics have led to significant progress of our understanding of dynamic systems. Prigogine proved that chemical species dynamically form an oscillatory pattern of minimum of ...
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Journal ArticleJournal of the Mechanics and Physics of Solids · January 1, 2015
Cnoidal waves are nonlinear and exact periodic stationary waves, well known in the shallow water theory of fluid mechanics. In this study we retrieve such periodic stationary wave solutions as singularities of the problem of homogeneous volumetric deformat ...
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Journal ArticlePure and Applied Geophysics · November 6, 2014
Shear zones in outcrops and core drillings on active faults commonly reveal two scales of localization, with centimeter to tens of meters thick deformation zones embedding much narrower zones of mm-scale to cm-scale. The narrow zones are often attributed t ...
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Journal ArticleGeophysical Research Letters · October 28, 2014
The exposed Glarus thrust displays midcrustal deformation with tens of kilometers of displacement on an ultrathin layer, the principal slip zone (PSZ). Geological observations indicate that this structure resulted from repeated stick-slip events in the pre ...
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Journal ArticleJournal of Geophysical Research: Solid Earth · June 1, 2014
During the last decade, knowledge over episodic tremor and slip (ETS) events has increased dramatically owing to the widespread installation of GPS and seismic networks. The most puzzling observations are (i) the periodic nature of slow seismic events, (ii ...
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Journal ArticleJournal of Geophysical Research: Solid Earth · January 1, 2014
In this paper, we study the behavior of a fluid-saturated fault under shear, based on the assumption that the material inside exhibits rate- and temperature-dependent frictional behavior. A creeping fault of this type can produce excess heat due to shear h ...
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Journal ArticleGeophysical Journal International · January 1, 2014
The segregation of melt from a linear viscous matrix is traditionally described by McKenzie's compaction theory. This classical solution overlooks instabilities that arise when non-linear solid matrix behaviour is considered. Here we report a closed form 1 ...
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Journal ArticleJournal of Geophysical Research: Solid Earth · January 1, 2014
This work studies the transient behavior of a chemically active, fluid-saturated fault zone under shear. These fault zones are displaying a plethora of responses spanning from ultrafast instabilities, like thermal pressurization, to extremely slow creep lo ...
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Journal ArticleGeotechnique Letters · November 19, 2013
The failure of geomaterials in localised shear bands is one of the most common features in geomechanics. Early studies have provided the necessary criteria for the conditions of localisation, inclination angle with respect to the loading axes and thickness ...
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Journal ArticleJournal of Structural Geology · May 1, 2012
In this paper we study the impact of thermal pressurization and mineral decomposition reactions under seismic deformation conditions (e.g., slip rates of about 1 m/s) triggered by shear heating, to the stability of a saturated fault material. By using high ...
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Journal ArticleInternational Journal for Numerical and Analytical Methods in Geomechanics · October 10, 2011
In this work, a new thermo-mechanical model is developed, applicable to large-scale, deep-seated landslides consisting of a coherent mass sliding on a thin clayey layer. The considered time window is that of catastrophic acceleration, starting at incipient ...
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Journal ArticleGranular Matter · June 1, 2011
Based on micromechanical considerations at the level of grain contacts and taking into account the way in which kinematic and static quantities are introduced at grain surface and grain centre, we identify appropriate measures related to energy dissipation ...
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Journal ArticleGranular Matter · June 1, 2011
Stability of undrained shearing in a classical Cauchy continuum has been first analyzed by Rice (J Geophys Res 80(11):1531-1536, 1975) who showed that instability occurs when the underlying drained deformation becomes unstable (i.e. in the softening regime ...
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Journal ArticleJournal of the Mechanics and Physics of Solids · September 1, 2010
In this paper we study the behavior of thermo-viscoplastic fault materials under steady shear. It is shown that during creep and at lower temperatures, the rate- and thermally dependent friction laws most commonly used could present similar mathematical an ...
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Journal ArticleEuropean Journal of Environmental and Civil Engineering · January 1, 2010
The problem of creeping landslides accompanied by heat production due to friction on their base is studied here. The landslide is modelled using a rigid block that slides over a clayey zone of finite width and a thermal softening and velocity strengthening ...
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Chapter · December 1, 2009
Catastrophic landslides are considered to slide dynamically under the presence of some weakening mechanism, like thermal pressurization, which reduces the strength of the slide near zero. In this study, based on energy considerations we model the run-off o ...
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Chapter · January 1, 2009
Catastrophic landslides are considered to slide dynamically under the presence of some weakening mechanism, like thermal pressurization, which reduces the strength of the slide near zero. In this study, based on energy considerations we model the run-off o ...
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Journal ArticleJournal of Geophysical Research: Earth Surface · September 24, 2007
The catastrophic Vaiont landslide (Southern Alps, Italy) of 9 October 1963 moved 2.7 × 108 m3 of rock that collapsed in an artificial lake, causing a giant wave that killed 1917 people. The landslide was preceded by 2-3 years of creep that ended with the f ...
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