Rémi Beguin

geophyConsult · Laboratoire d'érosion

Although geomembranes represent a very safe solution for old dams waterproofing, they may remain sensitive to damages from mechanical impacts of any type. In order to reduce this vulnerability, development of low-cost technologies that enable operators to immediately detect and locate leaks as soon as they appear are requested. A competitive techno...

Les digues des aménagements hydro-électriques du Rhône et du Rhin sont sensibles à un type d’érosion interne appelé érosion de contact et localisé aux interfaces sols fins/sols grossiers, notamment à l’interface noyau/fondation. Pour analyser ce phénomène, un programme de recherche a été mené conjointement par CNR et EDF depuis 2008, d’abord à l’éc...

Biocalcification is a recent in-situ soil consolidation solution. It is obtained by calcite precipitation under controlled biogeochemical conditions. The industrial process, for whose implementation Soletanche Bachy holds several patents, has been validated by several experiments, initially on laboratory scale and later in situ on industrial scale...

An innovative soil reinforcement method developed since 2004 is currently being adapted for hydraulic structures in the frame of the BOREAL project. The objective is to prevent mechanical failure of the soil due to internal erosion or liquefaction. The method is based on microbially induced urea-based carbonate precipitation. Four different erosion...

The Jet Erosion Test consists of impacting a soil sample with a water jet and analyzing the evolution of the scour depth in order. It was originally designed to assess the resistance of fine soils against overflowing erosion by modelling the headcut migration. To extend this research to the overflowing erosion of mixed coarse – fine soils, EDF and...

Seepage flow velocities are a key parameter to assess the risk of internal erosion in embankment hydraulic structures, such as embankment dams, canal embankments or levees. Accurate orders of magnitude of these seepage flow velocities are difficult to assess via conventional monitoring technologies or numerical modelling. EDF and geophyConsult have...

Sierroz embankments are located in an urban area, in the city of Aix-les-Bains (Savoie, France). Their linear is 400m on both rims. These embankments protect about 900 people against Sierroz river floods. Hydraulic studies performed in the frame of the Aix-les-Bains Inundation Risk Prevention Plan (PPRI in French) have shown that these embankments...

Le thème Recommandations du Projet National ERINOH (ERosion INterne dans les Ouvrages Hydrauliques) avait pour objectif de produire trois guides permettant de capitaliser les connaissances acquises pendant ces recherches. Le présent guide propose des recommandations sur l’emploi des méthodes de reconnaissance et de surveillance des digues et suggèr...

Zoned dams with clay cores and pervious shells (rockfill or gravel) are less vulnerable to failure than homogenous dams. However, under certain circumstances, such as piping in the foundation, pervious shells cannot provide enough weight or erosion resistance to stop concentrated leaks, the failure of Teton dam and near failure of Fontenelle dam, f...

After providing a brief presentation of the conditions leading to the occurrence of the contact erosion (CE) phenomenon in a structure, this chapter focuses on the problem of CE according to three different scales in order to deal with the subject as exhaustively as possible. The three different scales are at sample scale, at pore scale, and at hyd...

Contact erosion is potentially initiated at the interface between two soil layers by a groundwater flow within the coarser material. Once eroded by the flow, particles from the finer soil are transported through the pores of the coarser layer. Fluvial dikes are often exposed to this phenomenon. Small-scale experiments combining refractive index mat...

In Chapter 2, Rémi Beguin, Yves-Henri Faure and Pierre Philippe describe the contact erosion process, where particles of a fine soil are pulled by a water flow through a coarse zone in contact with the fine zone. Such interfaces between two soils of different grain sizes are frequently encountered in real earth embankments where the occurrence of c...

In Chapter 4, Rémi Béguin, Pierre Philippe, Yves-Henri Faure and Cyril Guidoux devote their attention to a still under-researched mechanism of erosion, but which can be found in numerous dikes: contact erosion between two types of soil. The description of the mechanisms that take place at grain level allows for a better understanding of the conditi...

Contact erosion is a type of internal erosion which occurs at the interface between two soil layers of different particle sizes. Particles from the fine soil (sand, silt, clay…) are pulled and driven by the flow through the pores of the surrounding coarse soil (gravel ...). Although its presence is suspected in many earthfill embankments, this proc...

European Working Group on Internal Erosion in Embankment Dams and Their Foundations

Contact erosion appears at the interface of two soil layers subject to a groundwater flow. Particles of the finer soil are eroded by the flow and transported through the pores of the coarser layer. Fluvial dykes are often exposed to this phenomenon. Small-scale experiments combining Refractive Index Matching medium, and Particle Image Velocimetry w...

Contact erosion occurs at the interface of two different soil layers when particles of the finer layer are removed by the flow and transported through the pores of the coarser layer. Whenever this kind of internal erosion occurs in embankment dams, dykes or in their foundations, severe consequences are likely. As contact erosion may be seen as a ty...

The forces snow avalanches are able to exert on protection dams or buildings are of crucial interest in order to improve avalanche mitigation measures and to quantify the mechanical vulnerability of structures likely to be damaged by snow avalanches. This paper presents an analytical model that is able to calculate these forces taking into account...

Under embankment dams and dykes, horizontal groundwater seepage prevails. If the subsoil is layered, and if some coarse layers are not appropriate filters for finer layers, there can be contact erosion at the interface between fine and coarse soils. In order to study contact erosion threshold, some base-soil and coarse-soil combinations were submit...

L'érosion de contact est un des risques majeurs d'érosion interne dans les digues. En présence d'un écoulement parallèle à l'interface, les particules de la couche de matériau fin sont érodées, puis transportées à travers les pores du matériau grossier. Une expérimentation spécifique a été réalisée pour comprendre les mécanismes gouvernant le détac...

We studied free-surface gravity-driven recirculating flows of cohesionless granular materials down a rough inclined plane and overflowing a wall normal to the incoming flow and to the bottom. We performed two-dimensional spherical particle discrete element simulations using a linear damped spring law between particles with a Coulomb failure criteri...

Considering the destructive power of dense snow avalanches, the design of avalanche defence dams implies a good understanding of the force those flows are able to exert on the structure. We simulated 2D dry granular flows down a rough inclined plane and overflowing a wall, for a large range of slope inclinations. We performed molecular dynamic simu...

The forces snow avalanches are able to exert on protection dams or buildings is of crucial interest in order to improve avalanche mitigation measures and to quantify the mechanical vulnerability of structures likely to be damaged by snow avalanches. This paper presents an analytical model that is able to calculate these forces taking into account d...