Publications associées à Swelling and shrinkage of partially saturated gas shales: from laboratory tests to an effective stress framework

Insights from an extensive triaxial testing campaign on a shale for comparative site characterization of a deep geological repository

Lyesse Laloui, Alessio Ferrari, Eleonora Crisci

Several boreholes were drilled for site comparison of a deep geological repository (DGR) in Northern Switzerland. The main target of the exploration program was the >100m thick Opalinus Clay, the designated host rock encountered at approximately 450 to 100 ...

Elsevier2024

Water weakening and the compressive brittle strength of carbonates: Influence of fracture toughness and static friction

Marie Estelle Solange Violay, Barnaby Padraig Fryer, Corentin Jean-Marie Rémi Noël

Water is ubiquitous within the pore space of rocks and has been shown to affect their physical and mechanical behaviour. Indeed, water can act on the rock strength via mechanical (i.e., reducing the effective stresses) or chemical effects (e.g., mineral di ...

2024

Frictional weakening leads to unconventional singularities during dynamic rupture propagation

Marie Estelle Solange Violay, François Xavier Thibault Passelègue, Federica Paglialunga, Mathias Alexandre David Lebihain

Earthquakes i.e. frictional ruptures, are commonly described by singular solutions of shear crack motions. These solutions assume a square root singularity order around the rupture tip and a constant shear stress value behind it, implying scale-independent ...

2024

Pore-pressure coefficients for unsaturated soils: generalized effective stress approach

Lyesse Laloui, Alessio Ferrari, Angelica Tuttolomondo

Geotechnical problems with total stress changes occurring rapidly relative to the soil consolidation time can be conveniently addressed using an effective stress-based approach. For saturated states, analytical formulations of pore-pressure coefficients ad ...

CANADIAN SCIENCE PUBLISHING2023

Drained Clay-Pipe Interface Resistance at Low Normal Stresses and Elevated Temperatures

Roba Houhou

Offshore pipelines that transport hydrocarbons under high pressure and high temperature are usually thermally insulated to maintain an elevated temperature and prevent any heat loss to the surroundings. However, the temperatures at the outer-wall of the pi ...

AMER SOC CIVIL ENGINEERS2023

A fully-coupled highly-parallelized geomechanical simulator for assessing induced seismicity

Jean-François Molinari, Guillaume Anciaux, Nicolas Richart, Brice Tanguy Alphonse Lecampion, Emil Gallyamov

Induced seismicity caused by anthropogenic modification of the subsurface effective stress state has been observed in a number of industrial applications -- from hydrocarbon extraction (e.g., Groningen [1]), drilling waste-water disposal (e.g., [2]) to the ...

2023

Single-Well Pore Pressure Preconditioning for Enhanced Geothermal System Stimulation

Marie Estelle Solange Violay, Barnaby Padraig Fryer, Mathias Alexandre David Lebihain

The stress state is an important parameter in terms of both earthquake nucleation and rupture. Here, a new stimulation technique is proposed for Enhanced Geothermal Systems (EGSs), which have previously been burdened with a number of high-profile incidence ...

2023

Propagation of planar three-dimensional buoyant hydraulic fractures

Andreas Möri

Hydraulic fractures are driven by an internal fluid pressure exceeding the minimum compressive stress, propagating in a direction perpendicular to the latter. This class of tensile fractures has gained interest over the last fifty years due to the developm ...

EPFL2023

Shearing and opening of a pre-existing discontinuity in response to fluid injection

Brice Tanguy Alphonse Lecampion, Ankit Gupta, Alexis Alejandro Sáez Uribe

We investigate the fluid-driven growth of a shear crack along a frictional discontinuity and its transition to hydraulic fracturing (sometimes referred to as hydraulic jacking) under plane-strain conditions. We focus on the case of a constant friction coef ...

2023

Shear strength and shear stiffness analysis of compacted Wyoming-type bentonite

Alessio Ferrari

Wyoming-type bentonite is one of the materials to be used as part of the Engineered Barrier System (EBS) in deep geological disposal facilities for the safe disposal of spent nuclear fuel.In the KBS-3 type repository, the canisters containing the spent fue ...

ELSEVIER2023

INFLUENCE OF VOIDS ON THICK DCB JOINT BEHAVIOR

Véronique Michaud, Anastasios Vassilopoulos, Jialiang Fan

The influence of voids on the quasi-static Mode I fracture performance of thick adhesive joints was investigated in this article. Double Cantilever Beam (DCB) joints were manufactured with glass fiber reinforced epoxy adherends and SikaPower®-830 epoxy adh ...

2023

Modeling the mechanics and rheology of porous and granular media: an elastoplastic continuum approach

Lars Kristoffer Uhlen Blatny

The complex mechanics of porous and granular media play a significant role in various industrial processes and natural phenomena. As an example, understanding the mechanics of how failure occurs, localizes and propagates in porous brittle solids under vari ...

EPFL2023

Hydro-mechanichal characterisation of bentonite/steel interfaces

Alessio Ferrari, Eleni Stavropoulou, Fabiana Sannasardo

The hydromechanical response of a Wyoming-type bentonite (MX-80) and its interface with steel was studied in terms of shear resistance under different hydration levels. A series of shear tests under constant normal stress were performed in total suction co ...

2023

Three-dimensional fluid-driven frictional ruptures: theory and applications

Alexis Alejandro Sáez Uribe

Fluid-driven frictional ruptures are important in a broad range of subsurface engineering technologies and natural earthquake-related phenomena. Some examples of subsurface operations where borehole fluid injections can induce frictional slip are deep geot ...

EPFL2023

Exploring the potential of the critical shear crack theory for reinforced and post-tensioned glass beams: Initial analysis and experiments

Alain Nussbaumer, Pieter Christian Louter, Jagoda Cupac

In the evolution of structural glass beam elements, the requirements for post-fracture load bearing capacity and safe failure behaviour have led to the development of reinforced and post-tensioned beams. Maximum bending capacity in the post-fracture state ...

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

Investigation of the effect of mineral dissolution on the geomechanical behaviour of geomaterials

Taeheon Kim

Geotechnical engineering scenarios engaged in internal erosion or mineral dissolution were found worldwide, from CO2 sequestration projects to internal erosion of earth dams. Materials subjected to loss of solid phase from their internal fabric vary from s ...

EPFL2022

Experimental quantification of 3D deformations in sensitive clay during stress-probing

Edward Carlo Giorgio Andò

Unique four-dimensional (4D) deformation data are collected during drained triaxial tests on intact specimens of a natural sensitive clay. This requires the development of a miniature triaxial cell for advanced stress path testing, specifically designed fo ...

ICE PUBLISHING2022

Life cycle environmental assessment of retaining walls in unsaturated soils

Alessio Ferrari, Gianluca Speranza

Retaining structures above groundwater level support soils that are usually in a state of partial saturation and subject to the actions of atmospheric agents. The current design approach considers the possible extremes of soil conditions - either totally d ...

ELSEVIER2022

Freezing-induced stiffness and strength anisotropy in freezing clayey soil: Theory, numerical modeling, and experimental validation

Gioacchino Viggiani, Edward Carlo Giorgio Andò

This paper presents a combined experimental-modeling effort to interpret the coupled thermo-hydro-mechanical behaviors of the freezing soil, where an unconfined, fully saturated clay is frozen due to a temperature gradient. By leveraging the rich experimen ...

WILEY2022