Numerical Simulation Study of Avalanches

Brugnot, Gérard; Pochat, R.

doi:10.1017/s0022143000011242

Cited by 27 publications

(11 citation statements)

References 1 publication

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“…In most current numerical simulations, snow avalanches are modelled by using the shallow-flow approximation (Brugnot & Pochat 1981;Eglit 1983;Bartelt et al 1999;Barbolini et al 2000). Although these recent developments are undoubtedly a promising approach in modelling snow avalanches, their level of sophistication contrasts with the crude current knowledge of snow rheology and avalanche physics as well as the poor quality of available field data.…”

Section: (A) Equations Of Motionmentioning

confidence: 99%

Monte Carlo calibration of avalanches described as Coulomb fluid flows

Ancey

2005

Phil. Trans. R. Soc. A.

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The idea that snow avalanches might behave as granular flows, and thus be described as Coulomb fluid flows, came up very early in the scientific study of avalanches, but it is not until recently that field evidence has been provided that demonstrates the reliability of this idea. This paper aims to specify the bulk frictional behaviour of snow avalanches by seeking a universal friction law. Since the bulk friction coefficient cannot be measured directly in the field, the friction coefficient must be calibrated by adjusting the model outputs to closely match the recorded data. Field data are readily available but are of poor quality and accuracy. We used Bayesian inference techniques to specify the model uncertainty relative to data uncertainty and to robustly and efficiently solve the inverse problem. A sample of 173 events taken from seven paths in the French Alps was used. The first analysis showed that the friction coefficient behaved as a random variable with a smooth and bell-shaped empirical distribution function. Evidence was provided that the friction coefficient varied with the avalanche volume, but any attempt to adjust a one-to-one relationship relating friction to volume produced residual errors that could be as large as three times the maximum uncertainty of field data. A tentative universal friction law is proposed: the friction coefficient is a random variable, the distribution of which can be approximated by a normal distribution with a volume-dependent mean.

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Section: (A) Equations Of Motionmentioning

confidence: 99%

Monte Carlo calibration of avalanches described as Coulomb fluid flows

Ancey

2005

Phil. Trans. R. Soc. A.

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“…[22] and they are the basis for the automatic mesh rezoning that will be discussed later. Finally, substituting ( 12) into ( 5) and applying the chain rule yields the relationship between the material time derivative and the referential time derivative:…”

Section: W;mentioning

confidence: 99%

“…f his problem, which has an approximate solution for an inviscid fluid flowing over a perfec frictionless bed, presents a formidable challenge when this solution is applied to mine tailings embankments. Attempts have been made to study this problem [26) or similar ones [5), btit too many assumptions are necessary in both the flow model and the material characterization. Here the finite element method allows a complete integration of the field equations and the use of constitutive models better suited to tailings.…”

Section: Numerical Examplesmentioning

confidence: 99%

Viscous flow with large free surface motion

Huerta

Liu

1988

Computer Methods in Applied Mechanics and Engineering

269

162

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An arbitrary Lagrangian-Eulerian (LE) Petrov-Galerkin finite elemen{technique is developed to study nonlinear viscous fluids under large free surface wave motion. A review of the kinematics and field equations from an arbitrary refe�ence is presented and since the major challenge of the ALE description lies in the mesh rezoning algorithm, various methods, including a new mixed formulation, are developed to update the mesh and lnap the moving domain in a more rational manner. Moreover, the streamline-upwind/Petrov-Galerkin formulation is implemented to accurately describe highly convective free surface flows. The effectiveness of the algorithm is demonstrated on a tsunami problem, the dam-break problem where the Reynolds number is taken as high as 3000, and a large-amplitude sloshing problem.

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“…From qualitative observations it seems evident that an avalanche passes through different stages of flow patterns, from the start in the fracture zone, to the track, and to the standstill in the runout zone. Hitherto for the whole movement the same mechanical model has been used, mostly the Voellmy model (Voellmy 1955), the similar and refined PCM and Salm models, or that of Brugnot and Pochat (1981).…”

Section: Flow Patterns Of Avalanching Snowmentioning

confidence: 99%

Measurement and Analysis of the Motion of Dense Flow Avalanches

Salm¹,

Gubler²

1985

A. Glaciology.

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Continuous avalanche flow speed measurements from start to sto p of dense flow avalanches, and localized flow depth and slope perpendicular flow speed profiles, have been measured using X-band radar equipment. Maximum flow speeds of up to 65 m/ s have been measured in large avalanches. Comparison of measured flow speeds with VoelIm y-type model ca1cula tions shows that traditionally chosen sets of parameters, evaluated from runout measurements, cannot model the measured high speeds in the track.

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Numerical Simulation Study of Avalanches

Cited by 27 publications

References 1 publication

Monte Carlo calibration of avalanches described as Coulomb fluid flows

Monte Carlo calibration of avalanches described as Coulomb fluid flows

Viscous flow with large free surface motion

Measurement and Analysis of the Motion of Dense Flow Avalanches

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