Publications associées à Roche volcanique

The influence of water-saturation on the strength of volcanic rocks and the stability of lava domes

Marie Estelle Solange Violay, Michael Heap

The rocks forming a volcanic edifice or dome are typically saturated or partially-saturated with water. However, most experiments aimed at better understanding the mechanical behaviour of volcanic rocks have been performed on dry samples, and therefore mos ...

2023

Elongated hydraulic fracture emerging from layers of alternating fracture toughness

Brice Tanguy Alphonse Lecampion, Carlo Peruzzo

Whether used to enhance the hydrocarbon production from low permeability rocks or to measure the minimum in-situ principal stress in rock formations, height growth of a hydraulic fracture above the formation of interest is a key metric for the design of su ...

2023

Reactivation of variably sealed joints and permeability enhancement in geothermal reservoir rocks

Alexandra Roma Larisa Kushnir, Michael Heap

Hydraulic stimulation of enhanced deep geothermal reservoirs commonly targets pre-existing joint networks with the goal of increasing reservoir permeability. Here, we study the permeability and strength of joint-free and jointed Buntsandstein sandstones fr ...

2023

Three-dimensional hydraulic fracture propagation in homogeneous and heterogeneous media

Carlo Peruzzo

Hydraulic fractures are tensile fractures that occur in solid materials due to the natural intrusion or anthropogenic injection of a viscous fluid into a fracture channel. The deliberate creation of hydraulic fractures is part of an industrial technology h ...

EPFL2023

Effect of femtosecond laser-induced high pressure on fused silica polymorphism

Arunkrishnan Radhakrishnan

High-pressure studies in silica are of great interest to earth and planetary sciences. Highpressure phases are rarely found in nature as a result of shock events like meteorite impacts or volcanic events in nature. Recreating these phases remains a challen ...

EPFL2022

Femtosecond laser-shockwave induced densification in fused silica

Yves Bellouard, Pieter Vlugter, Arunkrishnan Radhakrishnan, Julien Gilles Edgar Gateau

A tightly focused femtosecond laser-beam in the non-ablative regime can induce a shockwave sufficiently intense to reach local pressures in the giga-Pascal range or more. In a single beam configuration, the location of the highest-pressure zone is nested w ...

2022

Physical characterization of fault rocks within the Opalinus Clay formation

Marie Estelle Solange Violay, Luis Felipe Orellana Espinoza, Christophe Nussbaum

Near-surface disposal of radioactive waste in shales is a promising option to safeguard the population and environment. However, natural faults intersecting these geological formations can potentially affect the long-term isolation of the repositories. Thi ...

Nature Research2022

The Permeability of Porous Volcanic Rock Through the Brittle-Ductile Transition

Marie Estelle Solange Violay, Corentin Jean-Marie Rémi Noël, Gabriel Gérard Dominique Meyer, Michael Heap

The permeability of volcanic rock controls the distribution of pore fluids and pore fluid pressure within a volcanic edifice, and is therefore considered to influence eruptive style and volcano deformation. We measured the porosity and permeability of a po ...

2022

Experimental plastic reactivation of pseudotachylyte‐filled shear zones

Marie Estelle Solange Violay, François Xavier Thibault Passelègue

Pseudotachylytes are fine‐grained fault rocks that solidify from melt that is produced in fault zones during earthquakes. Exposed sections of natural fault zones reveal evidence of post‐seismic plastic deformation (i.e. reactivation) of pseudotachylyte, wh ...

2021

Studies on the mechanical evolution of compacted bentonite subjected to environmental actions

Jose Antonio Bosch Llufriu

Deep geological disposal is currently the most feasible option for the long-term isolation of radioactive waste, consisting in emplacing the waste into tunnels or drifts excavated at great depths in suitable geological formations. The use of bentonite, a h ...

EPFL2021

Rock strength properties of granitic rocks in Yosemite Valley, Yosemite National Park, California

Federica Sandrone, Michel Jaboyedoff

Yosemite National Park, located in the central part of California’s Sierra Nevada mountains, is a glacially carved landscape filled with iconic rock formations such as Cathedral Peak, El Capitan, and Half Dome. Igneous rocks, consisting primarily of variat ...

U.S. Geological Survey2020

Hydraulic stimulation of pre-existing discontinuities in tight rocks

Federico Ciardo

Hydraulic stimulation is an engineering technique whose aim is to enhance the permeability of fractured rock masses at depths ranging from one to five kilometers. It consists in the injection of fluid at sufficiently high pressure in order to shear pre-exi ...

EPFL2020

Pore space properties in carbonate fault rocks of peninsular Italy

Marie Estelle Solange Violay

The fault cores of extensional faults in Mesozoic limestones and dolostones are examined by mean of combined microstructural, ultrasonic and petrophysical analyses. Grain-supported fault rocks commonly localize in the outer fault cores, whereas matrix-supp ...

2019

From rock to magma and back again: The evolution of temperature and deformation mechanism in conduit margin zones

Marie Estelle Solange Violay, Michael Heap

Explosive silicic volcanism is driven by gas overpressure in systems that are inefficient at outgassing. The zone at the margin of a volcanic conduit-thought to play an important role in the outgassing of magma and therefore pore pressure changes and explo ...

Elsevier2017

Compression testing spherical particles for strength: Theory of the meridian crack test and implementation for microscopic fused quartz

Andreas Mortensen, Goran Zagar, Raphaël Charvet, Cyril Dénéréaz, Václav Pejchal

We show that uniaxial compression testing of spherical particles can give unambiguous access to their tensile strength as governed by surface flaws if one uses pairs of elasto-plastic platens, tailoring their hardness in order to control the relative area ...

2017

Short magmatic residence times of quartz phenocrysts in Patagonian rhyolites associated with Gondwana breakup

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner, Susanne Seitz

A key parameter in the study of magma evolution is the time scale on which magmatic processes occur. Using nanoscale secondary ion mass spectrometry (NanoSIMS), SIMS, and cathodoluminescence (CL) analyses, we have measured titanium (Ti) diffusion profiles ...

Geological Society of America2016

Analysis and estimation of gripper TBM performances in highly fractured and faulted rocks

Federica Sandrone, Jian Zhao, Erika Paltrinieri

This paper focuses on performance analysis of Tunnel Boring Machine (in particular gripper TBMs) in highly jointed rock masses and fault zones. In order to investigate possible relationships between these difficult excavation conditions and TBM performance ...

Elsevier2016

Efficient global optimization of reservoir geomechanical parameters based on synthetic aperture radar-derived ground displacements

Francesco Comola

When large volumes of fluids are removed from or injected into underground formations for, e.g., hydrocarbon and water production, CO_2 storage, gas storage, and geothermal energy exploitation, monitoring of surface deformations coupled to numerical modeli ...

Soc Exploration Geophysicists2016

The Interplay of In Situ Stress Ratio and Transverse Isotropy in the Rock Mass on Prestressed Concrete-Lined Pressure Tunnels

Anton Schleiss

This paper presents the mechanical and hydraulic behaviour of passively prestressed concrete-lined pressure tunnels embedded in elastic transversely isotropic rocks subjected to non-uniform in situ stresses. Two cases are distinguished based on whether the ...

Springer Wien2016

A hydromechanical approach to assess CO2 injection-induced surface uplift and caprock deflection

Lyesse Laloui, Chao Li

This study focuses on the derivation of a semi-analytical approach for the evaluation of surface uplift and caprock deflection induced by underground injection of CO2. The adopted methodology includes the development of a mathematical model that incorporat ...

2015