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Concept

Roche détritique

Publications associées (26)

Limits between surface and inner clogging of riverbed by fine sediment

Giovanni De Cesare, Romain Maxime Dubuis, Romain Dubuis

The deposition of fine sediment on top of the riverbed affects the reproduction of spawning fishes and some species of benthos. The clogging of the substrate resulting from this deposition is a well-known issue in rivers affected by anthropogenic activity ...

2023

The clogging of riverbeds: A review of the physical processes

Giovanni De Cesare, Romain Maxime Dubuis

Fine sediment represents an important part of the solid flux of rivers. Due to the size of these particles, they are often transported as suspended load. They gradually fill the pores of the substrate forming the hyporheic zone or cover the substrate by se ...

2023

Dynamics of Dual-Mode Bedload Transport With Three-Dimensional Alternate Bars Migration in Subcritical Flow: Experiments and Model Analysis

Mehrdad Kiani Oshtorjani

Bedload transport often exhibits dual-mode behavior due to interactions of spatiotemporal controlling factors with the migrating three-dimensional bedforms (characterized by the fully developed patterns in the bed, such as alternate bars, pools, and cluste ...

AMER GEOPHYSICAL UNION2023

Experimental Study on Bedload Transport and Bedforms: Behaviour and Interplay in Steep Turbulent Streams

Ivan Pascal

In mountain regions, steep streams play an important role in water and sediment connectivity. In these highly dynamic systems, water flow features, sediment fluxes and stream morphologies are tightly interlinked over a broad range of temporal and spatial s ...

EPFL2022

Hot rocks: Constraining the thermal conditions of the Mistastin Lake impact melt deposits using zircon grain microstructures

Cyril Cayron

The production of superheated melt during hypervelocity impact events has been proposed to be a common occurrence on terrestrial planetary bodies. Recent direct evidence of superheated impact melt temperatures exceeding > 2370 degrees C from the Kamestasti ...

ELSEVIER2022

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

Measurement of the inner structure of turbidity currents by ultrasound velocity profiling

Giovanni De Cesare

The inner velocity structure and particle concentration profile of opaque turbidity currents were mea- sured simultaneously by ultrasound velocity profilers. Currents consisting of a quartz particle suspension were generated by using the lock-exchange meth ...

2021

Arrest of a radial hydraulic fracture upon shut-in of the injection

Brice Tanguy Alphonse Lecampion, Andreas Möri

We investigate the propagation and arrest of a radial hydraulic fracture upon the end of the injection. Depending on the regime of propagation at the time of shut-in of the injection, excess elastic energy may be stored in the surrounding medium. Once the ...

2021

Brittle faulting of ductile rock induced by pore fluid pressure build‐up

Marie Estelle Solange Violay, François Xavier Thibault Passelègue, Corentin Jean-Marie Rémi Noël

Under upper crustal conditions, deformations are primarily brittle (i.e., localized) and accommodated by frictional mechanisms. At greater depth, deformations are ductile (i.e., distributed) and accommodated by crystal plasticity, diffusion mass transfer o ...

2021

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

Hypolimnetic oxygen depletion rates in deep lakes: Effects of trophic state and organic matter accumulation

Alfred Johny Wüest, Robert Vincent Schwefel, Beat Mueller

This study investigated the consumption of oxygen (O-2) in 11 European lakes ranging from 48 m to 372 m deep. In lakes less than similar to 100 m deep, the main pathways for O-2 consumption were organic matter (OM) mineralization at the sediment surface an ...

American Society of Limnology and Oceanography2020

Propagation of fluid driven fractures in transversely isotropic material

Fatima-Ezzahra Moukhtari

The propagation of fluid driven fractures is used in a number of industrial applications (well stimulation of unconventional reservoirs, development of deep geothermal systems) but also occurs naturally (magmatic dyke intrusion). While the mechanics of hyd ...

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

Statistical and physical characterization of rainfall-driven overland flow morphologies

Mohsen Cheraghi

Environmental transport processes are highly coupled with the shape of landscapes. Modern catchment analysis with high-resolution data and huge computational powers demand more detailed within-cell metrics for surface evolution modeling. This dissertation ...

EPFL2019

FVPM numerical simulation of the effect of particle shape and elasticity on impact erosion

François Avellan, Ebrahim Jahanbakhsh, Audrey Paulette Solange Maertens, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

The erosion of hydraulic machines by solid particle impacts is a widespread problem that leads to outage for expensive repairs, efficiency reduction, and cavitation enhancement. Numerical simulations can be used to study the phenomenon, provided they featu ...

ELSEVIER SCIENCE SA2019

Ecosystem engineers: Biofilms and the ontogeny of glacier floodplain ecosystems

Tom Ian Battin, Jade Brandani

The term “ecosystem engineering” emerged in the 1990s and is commonly used to refer to the activities of larger organisms like beavers and trees in rivers and streams. The focus on larger organisms may be motivated by their more visible effects on the envi ...

2019

Composition and superposition of alluvial deposits drive macro-biological soil engineering and organic matter dynamics in floodplains

Claire Guenat, Pascal Turberg, Rodolphe Schlaepfer, Andreas Cedric Schomburg

Soil structure formation in alluvial soils is a fundamental process in near-natural floodplains. A stable soil structure is essential for many ecosystem services and helps to prevent river bank erosion. Plants and earthworms are successful soil engineering ...

2019

Effect of dilatancy on the transition from aseismic to seismic slip due to fluid injection in a fault

Brice Tanguy Alphonse Lecampion, Federico Ciardo

Aseismic crack growth upon activation of fault slip due to fluid injection may or may not lead to the nucleation of a dynamic rupture depending on in-situ conditions, frictional properties of the fault and the value of overpressure. In particular, a fault ...

2019

Dynamic anticrack propagation in snow

Johan Alexandre Philippe Gaume

Continuum numerical modeling of dynamic crack propagation has been a great challenge over the past decade. This is particularly the case for anticracks in porous materials, as reported in sedimentary rocks, deep earthquakes, landslides, and snow avalanches ...

Nature Research2018

Design optimization of permeable sediment traps for fluvial bed load transport

Anton Schleiss, Sebastian Schwindt, Mona Jafarnejad Chaghooshi

Sediment traps are crucial elements for flood protection in mountain rivers with high sediment transport capacity. Existing structures often interrupt the channel connectivity. Ideally, a sediment trap should be permeable for bed load during non-hazardous ...

2018