Un modèle de recul des falaises pour évaluer les fréquences d'éboulement

Didier Hantz (1) , Lucilla Benedetti (2) , Didier Bourlès (2) , Julien Carcaillet (1)

1 ISTerre - Institut des Sciences de la Terre
2 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement

Quantitative assessment of diffuse rock fall hazard needs rock fall inventories, which are difficult to obtain for small or large rock fall volumes. In the case of localized hazard, a quantitative assessment is not possible in the present state of knowledge. A power law relation between rock fall frequency and volume is proposed for a better estimation of the frequencies. This relation has been used to build a rock wall retreat model, which can determine the age of the rock surface. The model has been applied to the calcareous cliffs of the Grenoble area. The calculated age is of the same order of magnitude than the mean age measured using the cosmogenic nuclides. The rock fall frequencies given by the power law relation can thus be used for a better estimation of diffuse and localized hazard, for the whole range of rock fall volumes.

Mots clés: Rock wall retreat; rock fall frequency

Domaines: Géologie appliquée

Didier Hantz, Lucilla Benedetti, Didier Bourlès, Julien Carcaillet. Un modèle de recul des falaises pour évaluer les fréquences d'éboulement. Journées Nationales de Géotechnique et de Géologie de l'Ingénieur 2012, Jul 2012, Bordeaux, France. p. 845-852. ⟨hal-00808588⟩