Estimating rock fall frequency in a limestone cliff using LIDAR measurements
GUERIN ; ROSSETTI ; HANTZ ; JABOYEDOFF
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Langue
anglais
Auteur
GUERIN ; ROSSETTI ; HANTZ ; JABOYEDOFF
Résumé / Abstract
Terrestrial Laser Scanner has been used to detect rock falls which have occurred in a limestone cliff during some years, in the difficult configuration of the Subalpine Chains. In a rock wall of width 750 m and height 200 m, 130 rock falls larger than 0.1 m3 have been detected for a period of 1180 days. The distribution of the rock fall volumes is well fitted by a power law, with an exponent which is compatible with the exponent found for the 120 km long cliffs of the Grenoble area. But the spatial-temporal frequencies given by the two analyses are very different. The number of rock falls larger than 1 m3, which occur per century and per hm2, is about 150 times larger for the bedded limestone of Sequanian stage than for the massive limestones of Tithonian and Barremian stages.
