A fragmentation-spreading model for long-runout rock avalanches
- 1 January 1999
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Geotechnical Journal
- Vol. 36 (6) , 1096-1110
- https://doi.org/10.1139/cgj-36-6-1096
Abstract
Based on the observation that deposits of large rock avalanches consist predominantly of intensely fragmented rock debris, it is proposed that the processes of rock fragmentation are significant causes of the peculiar distribution of mass in these deposits, and of the correspondingly long runout. Rock fragmentation produces high-velocity fragments moving in all directions, resulting in an isotropic dispersive stress within the translating rock mass. A longitudinal dispersive force consequently acts in the direction of reducing mass depth and tends to cause the rear part of the avalanche to decelerate and halt and the front part to accelerate. The result is greater longitudinal spreading of the travelling mass compared with nonfragmenting granular avalanches. The longer runout results from this additional fragmentation-induced spreading.Keywords
This publication has 2 references indexed in Scilit:
- A rock avalanche triggered by the October 1985 North Nahanni earthquake, District of Mackenzie, N.W.T.Canadian Journal of Earth Sciences, 1987
- The debris of the Frank Slide and theories of rockslide–avalanche mobilityCanadian Journal of Earth Sciences, 1986