000111446 001__ 111446 000111446 005__ 20181203020938.0 000111446 02470 $$2DAR$$a7129 000111446 02470 $$2ISI$$a000231538700004 000111446 037__ $$aARTICLE 000111446 245__ $$aMonte Carlo calibration of avalanches described as Coulomb fluid flows 000111446 269__ $$a2005 000111446 260__ $$c2005 000111446 336__ $$aJournal Articles 000111446 520__ $$aThe 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. 000111446 6531_ $$amonte carlo calibration 000111446 6531_ $$aavalanche 000111446 6531_ $$afluid flow 000111446 700__ $$0240366$$aAncey, Christophe$$g148669 000111446 773__ $$j363$$k1832$$q1529-1550$$tPhilosophical Transactions: A Mathematical, Physical & Engineering Sciences, The Royal Society 000111446 8564_ $$s308485$$uhttps://infoscience.epfl.ch/record/111446/files/Monte%20carlo%20calibration...%2C%20phil.trans.r.soc.A%2C%202005%2C%20363%2C%20Ancey%20LHE.pdf$$yn/a$$zn/a 000111446 909C0 $$0252029$$pLHE$$xU10257 000111446 909CO $$ooai:infoscience.tind.io:111446$$particle$$pENAC 000111446 917Z8 $$x106556 000111446 937__ $$aLHE-ARTICLE-2005-007 000111446 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED 000111446 970__ $$a11/LHE 000111446 980__ $$aARTICLE