- Title
- The significance of geology for the morphology of potentially unstable rocks
- Creator
- Fityus, S. G.; Giacomini, A.; Buzzi, O.
- Relation
- Engineering Geology Vol. 162, p. 43-52
- Publisher Link
- http://dx.doi.org/10.1016/j.enggeo.2013.05.007
- Publisher
- Elsevier BV
- Resource Type
- journal article
- Date
- 2013
- Description
- From a consideration of the concepts of geological weathering and structure, it can be expected that rockfall hazards should be characteristically different in different geological environments. This paper tests this idea by looking at the geometric characteristics of rock fragments formed on natural slopes in four different geological environments in Eastern Australia, where rockfall phenomena are often characterised by rolling of pre-detached debris. By measuring the three principle dimensions and making a systematic assessment of the shape characteristics of samples of rock debris in significant geological environments, it is found that the distributions of size and shape for the surface debris are statistically different. From the results, it is shown that the size and shape of debris is directly controlled by the rock type, its weathering characteristics and the structure of the parent rock mass. The severity of rockfall hazards is shown to be relatively lower in areas of Tertiary basalt, as the size of rolling fragments is limited by closely spaced fracturing inherited from its formation and the tendency to deteriorate further as it weathers deeply and rapidly. It is also lower in areas of Palaeozoic volcanics, since these tend to produce relatively angular fragments with higher proportions of fragments that are inherently more resistant to rolling. By contrast, thickly bedded sandstones form larger blocks with a larger proportion of shapes that are more prone to rolling. The size distribution of fragments is shown to be well approximated by a log-normal statistical distribution, and using the data provided in this study, it is possible to generate the size and shape data needed to undertake a stochastic assessment of rockfall trajectories in different geological environments.
- Subject
- rockfall hazard; rock fragment; block; size; shape; geology
- Identifier
- http://hdl.handle.net/1959.13/1299768
- Identifier
- uon:19937
- Identifier
- ISSN:0013-7952
- Rights
- © 2013. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
- Language
- eng
- Full Text
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