Engineering Transactions, 64, 1, pp. 105–113, 2016

Probabilistic method to determine the overall rock block failure based on failure mode

Hongze ZHAO
China University of Mining and Technology

Zequan LI
China University of Mining and Technology

Chi Seng KONG
China Railway Construction (HK) Limited

In rock slopes or underground excavations, due to the structure of the cutting surface, rock typically exhibits strong random properties, such as the structure of the surface geometry and mechanical parameters showed strong randomness, resulting in a high degree of rock mass uncertainty of the previous studies. In this paper, a new approach to estimating probability of failure of a rock block is proposed. Based on the previous studies investigating the potential failure of the block theory model, the block failure calculation took into account the geometrically formed probability, failure mode, and mechanical failure probability. As an engineering application of the presented model, the analysis of block failure, observed in a copper mine site in Australia, was performed. The Monte-Carlo simulation method was used for the evaluation where plane roughness, friction angle, and cohesion were considered as random variables. The results of this example show that the model can be used as a basis for evaluating the reliability of the block.
Keywords: jointed rock mass; key block theory; reliability theory
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Copyright © Polish Academy of Sciences & Institute of Fundamental Technological Research (IPPT PAN).


Feng P., Lajtai E.Z., Probabilistic treatment of the sliding wedge with EzSlide, Engineering Geology, 50(1): 153–163, 1998.

Lajtai E.Z., Carter B.J., Geoslide – A computer code on the IBM PC for the analysis of rock slopes, Department of civil and geological engineering, University of Manitoba, Winnipeg, Canada, 1989.

Glynn E.F., A probabilistic approach to the stability of rock slopes, Massachusetts, University of Cambridge, 1979.

Goodman R.E., Shi G.H., Block theory and its application to rock engineering, Wiley, New York, 1985.

Marek J.M., Savely J.P., Probabilistic analysis of the plane shear failure mode, Proceedings of 19th US Symposium on Rock Mechanics, Nevada, pp. 40–44, 1978.

Park H.J., West T.R., Development of a probabilistic approach for rock wedge failure, Engineering Geology, 59(3): 233–251, 2001.

Park H.J., West T.R., Woo I., Probabilistic analysis of rock slope stability and random properties of discontinuity parameters, Interstate Highway 40, Western North Carolina, USA, Engineering Geology, 79(3–4): 230–250, 2005.

Priest S.D., Hudson J.A., Estimation of discontinuity spacing and trace length using scan line surveys. International Journal of Rock Mechanics and Mining Sciences and Geomechanics, 18(3): 183–197, 1981.

Quek S.T., Leung C.F., Reliability-based stability analysis of rock excavations. International Journal of Rock Mechanics and Mining Sciences and Geomechanics, 32(6): 617–620, 1995.

Shi G.H., Goodman R.E., Geology and rock slope stability. Application of the key block concept for rock slopes, Proceeding of 3rd International Conference on Stability in Surface Mining, New York: AIME/SME, 1982.

Xu C., Dowd P., A new computer code for discrete fracture network modelling. Computer and Geosciences, 36(3): 292–301, 2010.

Zhang Q., Applied basic research and software development of block theory [in Chinese], Wuhan University, 2004.

Sun Y., Yao A., Liu X., Surrounding rock stability analysis method of fractured hard rock cavern [in Chinese], Rock and Soil Mechanics, 25(7): 1085–1088, 2004.

DOI: 10.24423/engtrans.326.2016