Energy-Based Method for Providing Soil Surface Erodibility Rankings

Marot, Didier; Regazzoni, Pierre-Louis; Wahl, Tony L.

doi:10.1061/(asce)gt.1943-5606.0000538

Cited by 54 publications

(40 citation statements)

References 5 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Flow in the JET is at steady state; hence, the effect of gravity on soil particles is negligible. Marot et al (2011) made a similar assumption in their JET and HET study. This assumption is only applicable in cohesive soils where particles are transported in suspension at the same speed as the eroding fluid.…”

Section: Development Of Semi-physically Based Modelmentioning

confidence: 78%

Development of semi-physically based model to predict erosion rate of kaolinite clay under different moisture content

et al. 2015

View full text Add to dashboard Cite

Understanding the susceptibility of soils to concentrated flow erosion is imperative for predicting sustainability of various engineering structures and assessing environmental integrity. Currently, a widely used model is empirical in nature. In this study, we developed a semi-physically based model that predicts the rate of concentrated flow erosion of kaolinite clay based on tensile and erodibility characteristics. To develop this model, direct tensile tests and jet erosion tests (JETs) were performed on kaolinite clay with different percent moisture contents (MCs). The direct tensile test results showed that the energy required to break interparticle bonds across a fracture plane and tensile strength decreases with an increase in MC, whereas the JET results showed that soil resistance to erosion decreases with an increase in MC. Results also showed that an efficiency index of the JET apparatus, which represents the fraction of jet power used in actual erosion processes, diminishes with a decrease in MC. This semi-physically based model predicted the rate of erosion of kaolinite clay for a range of MC and applied hydraulic shear stress. In model development and verification, 98% and 90% of the data, respectively, were within a discrepancy ratio of 0.50 and 2.0.Résumé : La compréhension de la susceptibilité des sols à l'érosion par écoulement concentré est essentielle pour prédire la durabilité de diverses structures d'ingénierie et pour évaluer l'intégrité environnementale. Présentement, un modèle largement utilisé est de nature empirique. Dans cette étude, nous avons développé un modèle semi-physique qui prédit le taux d'érosion par écoulement concentré d'une argile kaolinite basé sur des caractéristiques en tension et en érosion. Pour développer ce modèle, des essais en tension directe et des essais d'érosion en jet (JET) ont été réalisés sur l'argile kaolinite ayant différents contenus en humidité (CH). Les résultats des essais en tension directe ont démontré que l'énergie nécessaire pour briser les liens interparticules à travers un plan de rupture et la résistance en tension diminuent avec une augmentation du CH, tandis que les résultats JET ont démontré que la résistance du sol à l'érosion diminue avec une augmentation du CH. Les résultats ont aussi illustré qu'un indice d'efficacité de l'appareil JET, qui représente la fraction de la puissance du jet utilisé dans les processus d'érosion, diminue avec une diminution du CH. Ce modèle semi-physique a prédit le taux d'érosion de l'argile kaolinite pour une gamme de CH et de contraintes de cisaillement hydrauliques appliquées. Lors du développement et de la vérification du modèle, 98 et 90 % des données, respectivement, étaient à l'intérieur d'un indice de divergence de 0,50 et 2,0. [Traduit par la Rédaction] Mots-clés : érosion par écoulement concentré, modèle semi-physique, résistance en tension, contenu en humidité, sols cohésifs, argile kaolinite.

show abstract

Section: Development Of Semi-physically Based Modelmentioning

confidence: 78%

Development of semi-physically based model to predict erosion rate of kaolinite clay under different moisture content

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Such approach was first proposed to interpret results from jet erosion tests and hole erosion tests by Marot et al [15] and then adapted to suffusion [16]. The expression of the fluid flow power deduced from the energy conservation equation for the fluid phase involves four assumptions according to Marot et al [15,16]: (1) The fluid temperature is constant, (2) the system is adiabatic, (3) a steady-state flow is considered, and (4) as the value of Reynolds number is indicating a laminar flow [16], it is assumed that energy is mainly dissipated by viscous shear at the direct vicinity of solid particles and is thus representative of solid-fluid interactions [25]. Thanks to these assumptions, the flow power P flow expended by the fluid to seep through a homogeneous soil volume can be expressed by:…”

Section: Description Of the Eroded Mass For The First Erosion Phasementioning

confidence: 98%

“…Thanks to this modelling of porous media, the hydraulic shear stress along the horizontal capillary tube system can be expressed in terms of pressure gradient, porosity and intrinsic permeability of the soil. Another approach, which does not need any assumption regarding the granular matter fabric, was developed to interpret results from the jet erosion tests (JET) and the hole erosion tests (HET), and it is based on the power expended by the seepage flow [15,16]. In such approach, changes of hydraulic soil characteristics are implicitly taken into account through the flow power.…”

Section: Introductionmentioning

confidence: 99%

A description of internal erosion by suffusion and induced settlements on cohesionless granular matter

2015

Self Cite

View full text Add to dashboard Cite

International audienceCohesionless granular matter subjected to internal flow can incur an internal erosion by suffusion characterized by a migration of its finest constituting particles. A series of suffusion tests is performed on assemblies of gap graded glass beads using a large oedo-permeameter device. Two successive processes of erosion can be observed during the tests. First, a suffusion process is characterized by a progressive and diffuse migration of fine particles over a long time period. The second process, induced by the first one, is characterized by a strong migration over a short time period (blowout of fine particles) and produces rapidly large settlement of specimen. Time series of hydraulic conductivity, longitudinal profile of specimen density, eroded mass and axial deformation are analyzed. The initial content of fine particles and the history of hydraulic loading appear as key parameters in the suffusion development. To characterize the suffusion development, erosion rate is investigated according to the power expended by the seepage flow, and a new law of erosion by suffusion is proposed

show abstract

“…Inspired by the energy approach of Marot and coworkers and also by the thermodynamic implication (Equation ), we suggest the following local suffusion law:

{\overset{falsê}{ρ}}^{F} = k_{α} \frac{k_{F}}{ρ_{F} g} {[\nabla p_{F} - ρ_{F} g]}^{2} = k_{α} P_{seepage}

where

k_{α} = 10^{- I_{α}}

is the coefficient of erodibility of the material, which is an intrinsic property, k F is the hydraulic conductivity, and g is the vertical component of the gravity vector. The right‐hand side term of Equation is in fact the product between k α and the volumetric power dissipated by the flow P seepage . The erosion resistance index I α was found to be independent of the hydraulic loading and of the sample's size upon several laboratory scale studies …”

Section: A Case Study For Soil Suffusionmentioning

confidence: 99%

Modelling of internal erosion based on mixture theory: General framework and a case study of soil suffusion

Bui

Gelet

Marot

2019

Num Anal Meth Geomechanics

Self Cite

View full text Add to dashboard Cite

Summary A general thermo‐hydro‐mechanical framework for the modelling of internal erosion is proposed based on the theory of mixtures applied to two‐phase porous media. The erodible soil is partitioned in two phases: one solid phase and one fluid phase. The solid phase is composed of nonerodible grains and erodible particles. The fluid phase is composed of water and fluidized particles. Within the fluid phase, species diffuse. Across phases, species transfer. The modelling of internal erosion is contributed directly by mass transfer from the solid phase towards the fluid phase. The constitutive relations governing the thermomechanical behaviour, generalised diffusion, and transfer are structured by the dissipation inequality. The particular case of soil suffusion is investigated with a focus on constitutive laws. A new constitutive law for suffusion is constructed based on thermodynamic conditions and experimental investigations. This erosion law is linearly related to the power of seepage flow and to the erosion resistance index. Owing to its simplicity, this law tackles the overall trend of the suffusion process and permits the formulation of an analytical solution. This new model is then applied to simulate laboratory experiments, by both analytical and numerical methods. The comparison shows that the newly developed model, which is theoretically consistent, can reproduce correctly the overall trend of the cumulated eroded mass when the permeability evolution is small. In addition, the results are provided for four different materials, two different specimen sizes, and various hydraulic loading paths to demonstrate the applicability of the new proposed law.

show abstract

Energy-Based Method for Providing Soil Surface Erodibility Rankings

Cited by 54 publications

References 5 publications

Development of semi-physically based model to predict erosion rate of kaolinite clay under different moisture content

Development of semi-physically based model to predict erosion rate of kaolinite clay under different moisture content

A description of internal erosion by suffusion and induced settlements on cohesionless granular matter

Modelling of internal erosion based on mixture theory: General framework and a case study of soil suffusion

Contact Info

Product

Resources

About