Publications associées à Study on rock mass boreability by TBM penetration test under different in situ stress conditions

Reinforcement Learning for Outdoor Balloon Navigation: A Successful Controller for an Autonomous Balloon

Autonomous ballooning allows for energy-efficient long-range missions but introduces significant challenges for planning and control algorithms, due to their single degree of actuation: vertical rate control through either buoyancy or vertical thrust. Late ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2024

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

Michael Heap, Alexandra Roma Larisa Kushnir

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

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

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

Michel Jaboyedoff, Federica Sandrone

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

A numerical study on the coupled hydro-mechanical behaviour of compacted bentonite

Lyesse Laloui, Alessio Ferrari, Jose Antonio Bosch Llufriu

Understanding the mechanical behaviour of compacted bentonite upon re-saturation is of outmost importance in most designs of nuclear waste disposal repositories. The behaviour of bentonite is characterized by its stress-path dependency and it is typically ...

EDP SCIENCES2020

A proof of equivalence of two force methods for active structural control

Arka Prabhata Reksowardojo, Gennaro Senatore

This paper gives a proof of equivalence between two existing force methods (FM) for structural analysis: The Integrated Force Method (IFM) and a force method based on singular value decomposition (SVD) of the equilibrium conditions here named as SVD-FM. Re ...

2020

Variations in elastic and electrical properties of crustal rocks with varying degree of microfracturation

Luis Felipe Orellana Espinoza, Marie Estelle Solange Violay, Lucas Xan Pimienta

This work aims at investigating the effect of varying degrees of microfracturing on the joint elastic and electrical transport properties of rocks. Different crustal rocks were subjected to Thermal Treatment, expected to induce microfracturing, up to diffe ...

2019

The influence of different hydro-mechanical paths on final properties of saturated MX80 bentonite samples

Lyesse Laloui, Alessio Ferrari, Patrycja Ewelina Baryla

Compacted bentonite is considered to be used for deep geological nuclear waste disposal due to its isolation properties such as low permeability, solute retention and swelling pressure. To ensure that these properties will remain favourable throughout the ...

2018

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

Stresses and displacements in steel-lined pressure tunnels and shafts in anisotropic rock under quasi-static internal water pressure

Anton Schleiss, Alexandre Jean Pachoud

Steel-lined pressure tunnels and shafts are constructed to convey water from reservoirs to hydroelectric power plants. They are multilayer structures made of a steel liner, a cracked backfill concrete layer, a cracked or loosened near-field rock zone and a ...

Springer Wien2016

The role of mass-transport deposits and turbidites in shaping modern lacustrine deepwater channels

Nicolas Le Dantec

Subaquatic canyons are an important pathway for sediment transport into oceanic and lacustrine basins. Understanding the mechanisms governing their geomorphological evolution is a key to predict the sediment distribution patterns through these sediment con ...

Elsevier2016

Inter-operator Reliability of Magnetic Resonance Image-Based Computational Fluid Dynamics Prediction of Cerebrospinal Fluid Motion in the Cervical Spine

Nikolaos Stergiopoulos, Bryn Andrew Martin

For the first time, inter-operator dependence of MRI based computational fluid dynamics (CFD) modeling of cerebrospinal fluid (CSF) in the cervical spinal subarachnoid space (SSS) is evaluated. In vivo MRI flow measurements and anatomy MRI images were obta ...

Springer2016

Analysis of TBM tunnelling performance in faulted and highly fractured rocks

Erika Paltrinieri

The thesis focuses on the study of the performance of TBMs in highly jointed and faulted rocks. Despite the great production rates recorded in favourable ground conditions, the TBM advance can be significantly slowed down in limiting geological situations ...

EPFL2015

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

A Microstructure-Based Model to Characterize Micromechanical Parameters Controlling Compressive and Tensile Failure in Crystallized Rock

Jian Zhao, Tohid Kazerani

A discrete element model is proposed to examine rock strength and failure. The model is implemented by UDEC which is developed for this purpose. The material is represented as a collection of irregular-sized deformable particles interacting at their cohesi ...

Springer Verlag2014

Effects of rock mass anisotropy on deformations and stresses around tunnels during excavation

Anton Schleiss

rock mass where the in situ state of stress is uniform. The rock mass was assumed to behave elastically and two cases were examined: whether the rock mass has an isotropic elastic property or not. A two-dimensional plain strain elastic-plastic Jointed Rock ...

2014

Coupled Approach to Assess Caprock Deformation Caused by CO2 Injection

Lyesse Laloui, Chao Li

This study focuses on a specific problem related to the caprock deformation induced by the injection of CO2 at depth. The adopted methodology includes the development of a mathematical model that incorporates the deformable behaviour of storage media and t ...

ASCE2014

Quasi-static and dynamic fracture behaviour of rock materials: phenomena and mechanisms

Jian Zhao, Qianbing Zhang

An experimental investigation is conducted to study the quasi-static and dynamic fracture behaviour of sedimentary, igneous and metamorphic rocks. The notched semi-circular bending method has been employed to determine fracture parameters over a wide range ...

Springer Verlag2014

Sediment dynamics in the subaquatic channel of the Rhone delta (Lake Geneva, France/Switzerland)

Nicolas Le Dantec

With its smaller size, well-known boundary conditions, and the availability of detailed bathymetric data, Lake Geneva's subaquatic canyon in the Rhone Delta is an excellent analogue to understand sedimentary processes in deep-water submarine channels. A mu ...

Springer Verlag2014