Impact of Scale on Rock Strength

Authors: Roland Pusch, Richard Weston

Abstract:

The scale dependence of the strength of virtually homogeneous rock is usually considered to be insignificant but the spectrum of discontinuities plays a very important role for the strength of differently sized rock elements and also controls the rock creep strain. Large-scale load tests comprised recording of the creep strain rate that was found to be strongly retarded and negligible for stresses lower than about 1/3 of the failure load. For higher stresses creep took place according to a log time law representing secondary creep that ultimately changed to tertiary creep and failure.

Keywords: Impact of scale, rock strength.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1055210

References:

[1] Pusch, R., Yong, R.N., Nakano, M., High-level Radioactive Waste Disposal, WIT Press, Southampton, UK, 2011.
[2] Liedtke, L., Shao, H., Alheid, H. J., Sönnke, J., "Material Transport in Fractured Rock - Rock Characterization in the Proximal Tunnel Zone" Federal Institute for Geosciences and Natural Resources, Hannover, Germany, 1999
[3] Pusch, R., Adey, R., Accurate computation of stress and strain of rock with discontinuities. Advances in Computational Structural Mechanics, Civ. Comp. Ltd, Edinburgh, Scotland, 1998, pp.233-236.
[4] Whittaker, B.N., Singh, R.N., Sun, G., Rock Fracture Mechanics, Developments in Geotechnical Engineering, 71. Elsevier Publ. Co., 1992.
[5] Martin, D., "Brittle Rock Strength" TVO & SKB Workshop, Nuclear Waste Management, TVO technology project, Work Report TEKA- 94.07, Helsinki, 1994.
[6] Pusch, R., Rock Mechanics on a Geological Base, Developments in Geotechnical Engineering, 77. Elsevier Publ. Co, 1995.
[7] Pusch, R., "Creep in rock as a stochastic process" Engineering Geology, Vol.20, 1984, pp.301-310.