Now at: Department of Geography, Trinity College Dublin, Dublin 2, Eire.
The relationship of porosity and angle of repose to mixture proportions in assemblages of different sized materials
Article first published online: 14 JUN 2006
Volume 21, Issue 1, pages 149–162, February 1974
How to Cite
STATHAM, I. (1974), The relationship of porosity and angle of repose to mixture proportions in assemblages of different sized materials. Sedimentology, 21: 149–162. doi: 10.1111/j.1365-3091.1974.tb01786.x
- Issue published online: 14 JUN 2006
- Article first published online: 14 JUN 2006
- Manuscript received 7 May 1973; revision received 5 August 1973
Rotating drum experiments on the repose angles of mixtures of glass spheres have shown that φr (angle of shear) is strongly influenced by the proportions of the mixture. It was found that φr reached a peak value for the minimum porosity mixture; where the pore spaces between the large particles were just filled with small material; which was attributed to increased dilatation on the shear plane during avalanching. The geomorphic significance of these observations, in terms of slope development, is discussed.
Secondly, the results of the experiments showed that, although more constant than φi (limiting angle of repose), φr was subject to some variation. Thus φr, as measured in a rotating drum, is not a true constant and can not be exactly analogous to φ'cv (angle of internal sliding friction at constant volume) as measured in a shearbox test—as has been previously suggested. It is tentatively suggested that at least some of the variability in φr is attributable to the magnitude of the immediately preceding value of φi, in that an unusually high value of φi, favours a lower value of φr due to the greater amount of kinetic energy released on failure.