Centrifuge modelling of capillary rise

Depountis, Nikolaos; Davies, M. C. R.; Harris, C.C.; Burkhart, Scott C.; Thorel, Luc; Rezzoug, A.; König, Diethard; Merrifield, C. M.; Craig, William H.

doi:10.1016/s0013-7952(00)00092-2

Cited by 17 publications

(11 citation statements)

References 2 publications

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“…On the applied side, capillary rise plays a major role in the imbibition of porous media (Kistler 1993;Steen 1996;Lago & Araujo 2001;Marmur 2003). Its main applications are, among others, in soil imbibition (Depountis et al 2001;Ramrez-Flores, Bachmann & Marmur 2010), wicking in textiles (Ferrero 2003), flows in foams (Caps et al 2005) or powders (Galet, Patry & Dodds 2010) and civil engineering materials (Karoglou et al 2005;Hall & Hoff 2007). In all these examples, the geometry of the porous media is far from a collection of cylindrical tubes and the applicability of Jurin's and Lucas-Washburn's laws can be questioned (van Brakel & Heertjes 1975;Lago & Araujo 2001).…”

Section: Introductionmentioning

confidence: 99%

A universal law for capillary rise in corners

2011

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International audienceWe study the capillary rise of wetting liquids in the corners of different geometries and show that the meniscus rises without limit following the universal law: h(t)/a ≈ (ɣt/na)⅓, where ɣ and n stand for the surface tension and viscosity of the liquid while a =√γ /ρɣ g is the capillary length, based on the liquid density p and gravity g. This law is universal in the sense that it does not depend on the geometry of the corner. © 2011 Cambridge University Press

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Section: Introductionmentioning

confidence: 99%

A universal law for capillary rise in corners

2011

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“…9 Meltwater migration and fractionation processes (Souchez & Lorrain 1991), which are stress gradient and temperature dependent, are readily modelled. Indeed, much work has already been completed on the migration of water through granular materials (Depountis et al 1999) in centrifuge models.…”

Section: Discussionmentioning

confidence: 99%

Physical modelling of the rheology of clean and sediment-rich polycrystalline ice using a geotechnical centrifuge: potential applications

Irving

Rea

Harris

2000

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A self-weight stress gradient is developed through the body of a glacier such that strain rates are highest in the lowest few metres as described by Glen's floow law and other stress-and temperature-dependent relationships. Conventional laboratory technology limits the size and complexity of physical models of glacier ice, particularly in the complicated basal ice layers. A geotechnical centrifuge can be used to replicate such stress regimes in a controlled environment using a scaled model of the field 'prototype' that is subjected to an accelerational field that is a factor N greater than that of the Earth, g. The development of a technique employing a geotechnical centrifuge as a testbed for such physical models is described. Strain rates of 10-6-10 -7 S -l are calculated for models of low and moderate stress, high temperature ice. Relationships between the physical models and glacial systems suggest a scaling of the effects of transient creep by 1 : N, diffusion creep by 1 : N2-1 : N 3 and power law creep by 1 : 1. Preliminary results demonstrate the potential applications of the technique in the fields of glaciology and glacial geomorphology, in particular where low stresses and high temperatures are key characteristics of a glacial system and in systems containing several stratigraphic units.The studied mechanical behaviour of ice has generally been conducted using triaxial and uniaxial rigs in which stresses are applied to samples along one or more axes. In the case that the confining stress is greater than the applied stress, the deformation of the sample is generally expressed as a conical pair of shear zones as shown schematically in Fig. l a. In this configuration, the departures from the true stress field in a glacier can be summarized as follows.9 The sample size limits the grain size which can be used in the sample (Baker 1981) before grain size becomes volumetrically significant. Stress is localized in the larger grains and the resultant shear strain is modified by this effect. 9 The size of the shear zone is governed by the end platens and the sample length. 9 The shear zones are conical and hence have a point discontinuity.Appropriate laboratory and mathematical methods have minimized the effects of the last two factors to allow testing at small grain sizes to be conducted. However, grain sizes in excess of 10mm are common in ice bodies at high homologous temperatures as a result of dynamic recrystallisation (Paterson 1994).A more effective laboratory technique is now introduced that allows large models of appropriate geometry to be tested under the correct stress regime. This method employs a geotechnical beam centrifuge to apply an acceleration so that self weight stress increases linearly with depth through a large (maximum 0.5 • 0.7 • 0.2 m) model in a controlled environment. Such a model size allows spatially varying composition and structure as observed in the field (known as the prototype) to be replicated in the laboratory as shown in Fig. lb. This paper presents a methodology developed fo...

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“…Alongside the scaling laws listed in Table 1, two additional scaling laws must be specified for partially saturated soils, namely for capillary rise and its development rate. As pointed out by Depountis et al (2001), the scaling laws for the capillary rise and the rate of capillary rise are, respectively, 1=N and 1=N². If a homogeneous soil is placed in the right column of Fig.…”

Section: Centrifuge Technique and Scaling Lawsmentioning

confidence: 94%

“…1. Scheme of column model apparatus by Depountis et al (2001) to derive the scaling laws for the capillary rise and the rate of capillary rise: homogeneous soil in the right column connected to a water tube and subjected to a uniform Ng acceleration field Table 2. The soil is classified as sandy silt and its grain distribution curve is moderately steep.…”

Section: Centrifuge Technique and Scaling Lawsmentioning

confidence: 99%

Face stability of shallow tunnels in partially saturated soil: centrifuge testing and numerical analysis

Soranzo

Tamagnini

2015

Géotechnique

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In this paper the face stability of shallow tunnels in partially saturated soil is investigated by means of centrifuge testing and numerical analysis. A loess soil is chosen for this study and its properties are characterised by laboratory testing. Centrifuge model tests are carried out at different soil densities and with different depths of water table. The numerical analyses are performed with an advanced constitutive model for partially saturated soil. The constitutive model is implemented in a finite-element code using the Bishop's effective stress. The model parameters are calibrated based on drained triaxial compression tests on partially saturated soil. The wetting collapse of the tunnel face is simulated by imposing a zero pore pressure condition at the ground surface. The numerical results are compared with the centrifuge tests.

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Centrifuge modelling of capillary rise

Cited by 17 publications

References 2 publications

A universal law for capillary rise in corners

A universal law for capillary rise in corners

Physical modelling of the rheology of clean and sediment-rich polycrystalline ice using a geotechnical centrifuge: potential applications

Face stability of shallow tunnels in partially saturated soil: centrifuge testing and numerical analysis

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