Analysis of volumetric internal erosion in cohesionless soils: Model, experiments and simulations

2021 ◽  
Author(s):  
Rachel Gelet ◽  
Alaa Kodieh ◽  
Didier Marot ◽  
Ngoc‐Son Nguyen
Keyword(s):  
Internal Erosion ◽  
Cohesionless Soils ◽  
Model Experiments

Combined Geometric Hydraulic Criteria Approach for Piping and Internal Erosion in Cohesionless Soils

2018 ◽  
Vol 42 (1) ◽  
pp. 20170096 ◽  
Author(s):  
Marx Ferdinand Ahlinhan ◽  
Codjo Edmond Adjovi
Keyword(s):  
Internal Erosion ◽  
Cohesionless Soils

scholarly journals Modelling internal erosion of cohesionless soils using a microstructural parameter

PAMM ◽  
2010 ◽  
Vol 10 (1) ◽  
pp. 355-356 ◽  
Author(s):  
Christian Becker ◽  
Patrick Kurzeja ◽  
Holger Steeb
Keyword(s):  
Internal Erosion ◽  
Microstructural Parameter ◽  
Cohesionless Soils

scholarly journals Investigation of Internal Erosion Susceptibility of Core Soil from Three Dams

2021 ◽  
Vol 10 (2) ◽  
pp. 59-68
Author(s):  
Ahmed Jalil ◽  
Ahmed Benamar ◽  
Mohamed Ebn Touhami
Keyword(s):  
Laboratory Tests ◽  
Clay Content ◽  
Soil Classification ◽  
Internal Erosion ◽  
Cohesionless Soils ◽  
Erosion Coefficient ◽  
A Cell ◽  
Erosion Test ◽  
Core Soil

Laboratory tests on internal erosion of cohesionless soils are often performed on cells submitted to a controlled seepage. The cell dimension depends on the grain size of tested soil and must meet the geometric and hydraulic scale requirements as regards to the modeled process. Three specimens collected from different zoned dams in Morocco were characterized for their geotechnical properties and dispersion sensitivity, and then submitted in two different cells to internal erosion (Hole Erosion Test) under controlled seepage. The erosion kinetics was measured, and soil classification was assessed as regards to the useful engineering guidelines. The results showed that specimen dimensions can affect the erosion parameters which are quite different from a cell to another. Even though the derived erosion coefficient values are different from the two testing cells, the classification of the three soils regarding the susceptibility to erosion, using engineering guidelines, indicated that the tested soils fall overall in neighboring erosion classifications. However, the soil involving the lower clay content provided the greatest resistance against internal erosion.

Filter testing of broadly graded cohesionless tills

1984 ◽  
Vol 21 (4) ◽  
pp. 634-643 ◽  
Author(s):  
Jean Lafleur
Keyword(s):  
Grain Size ◽  
Preliminary Test ◽  
Internal Erosion ◽  
Earth Dam ◽  
Laboratory Simulation ◽  
Core Material ◽  
Test Results ◽  
Cohesionless Soils ◽  
Filtration Process ◽  
Margin Of Safety

Filter criteria have generally been checked experimentally with relatively uniform bases (protected soils). However, these criteria may not be applicable when nonuniform soils are used, especially broadly graded cohesionless tills with nonlinear grain size curves. Such soils were extensively used at the James Bay project as impervious core material, and a testing programme was undertaken to establish the margin of safety associated with the application of current filter criteria: the design was based on the arbitrarily defined portion of the base soil grain size curve. Also, a more general objective of the programme was to assess the role that self-filtration plays in the filtration process of such broadly graded cohesionless soils.This paper presents and discusses the factors that have been found relevant in the development of a representative laboratory simulation of the complex filtration phenomenon; namely, maximum particle size, density, saturation of the samples, direction of flow, intensity of the gradients, and development of hydraulic fracturing. Some preliminary test results are given for a till from the LG-3 dam that showed a marked bend in the grain size curve at [Formula: see text]. It is seen that particles coarser than this size do not significantly influence the self-filtration process. Finally, the test results demonstrate that the filters specified for the LG-3 project are more than adequate. Key words: earth dam, filtration, broadly graded cohesionless soils, internal erosion, laboratory tests, design.

Spatial and temporal progression of internal erosion in cohesionless soil

2011 ◽  
Vol 48 (3) ◽  
pp. 399-412 ◽  
Author(s):  
Ricardo Moffat ◽  
R. Jonathan Fannin ◽  
Stephen J. Garner
Keyword(s):  
Seepage Flow ◽  
Hydraulic Gradient ◽  
Internal Erosion ◽  
Cohesionless Soil ◽  
Cohesionless Soils ◽  
Multi Stage ◽  
Internal Instability ◽  
Post Test ◽  
Erosion Test ◽  
Permeameter Tests

Permeameter tests were performed on four widely graded cohesionless soils, to study their susceptibility to internal erosion. Test specimens were reconstituted as a saturated slurry, consolidated, and then subjected to multi-stage seepage flow under increasing hydraulic gradient. The occurrence of internal instability is described qualitatively, from visual observations through the wall of the permeameter during a test and from post-test observations; it is also described quantitatively, from change of hydraulic gradient within the specimen and from axial displacement during a test. The results provide a novel insight into the spatial and temporal progression of seepage-induced internal instability. This insight yields an improved characterization of suffusion and suffosion in cohesionless soils, the progression of which appears governed by a critical combination of hydraulic gradient and effective stress.

Cognitive Components of Ingroup Projection

2014 ◽  
Vol 45 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Maya Machunsky ◽  
Thorsten Meiser
Keyword(s):  
Mental Representation ◽  
Cognitive Representation ◽  
Social Categories ◽  
Projection Model ◽  
Minimal Group ◽  
Model Experiments ◽  
Superordinate Category ◽  
Cognitive Components ◽  
Per Se

This research investigated whether relative ingroup prototypicality (i.e., the tendency to perceive one’s own ingroup as more prototypical of a superordinate category than the outgroup) can result from a prototype-based versus exemplar-based mental representation of social categories, rather than from ingroup membership per se as previously suggested by the ingroup projection model. Experiments 1 and 2 showed that a prototype-based group was perceived as more prototypical of a superordinate category than an exemplar-based group supporting the hypothesis that an intergroup context is not necessary for biased prototypicality judgments. Experiment 3 introduced an intergroup context in a minimal-group-like paradigm. The findings demonstrated that both the kind of cognitive representation and motivational processes contribute to biased prototypicality judgments in intergroup settings.

Influence of Rim Run-Out on the Nonuniformity of Tire-Wheel Assemblies

1994 ◽  
Vol 22 (2) ◽  
pp. 99-120 ◽  
Author(s):  
T. B. Rhyne ◽  
R. Gall ◽  
L. Y. Chang
Keyword(s):  
Finite Element ◽  
Radial Force ◽  
Membrane Model ◽  
Model Experiments ◽  
Force Variation ◽  
One To One ◽  
The One

Abstract An analytical membrane model is used to study how wheel imperfections are converted into radial force variation of the tire-wheel assembly. This model indicates that the radial run-out of the rim generates run-out of the tire-wheel assembly at slightly less than the one to one ratio that was expected. Lateral run-out of the rim is found to generate radial run-out of the tire-wheel assembly at a ratio that is dependent on the tire design and the wheel width. Finite element studies of a production tire validate and quantify the results of the membrane model. Experiments using a specially constructed precision wheel demonstrate the behavior predicted by the models. Finally, a population of production tires and wheels show that the lateral run-out of the rims contribute a significant portion to the assembly radial force variation. These findings might be used to improve match-mounting results by taking lateral rim run-out into account.

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