Slope stability probability classification

The slope stability probability classification (SSPC)^[1][2] system is a rock mass classification system for slope engineering and slope stability assessment. The system is a three-step classification: ‘exposure’, ‘reference’, and ‘slope’ rock mass classification with conversion factors between the three steps depending on existing and future weathering and damage due to method of excavation. The stability of a slope is expressed as probability for different failure mechanisms.

A rock mass is classified following a standardized set of criteria in one or more exposures (‘exposure’ classification). These values are converted per exposure to a ‘reference’ rock mass by compensating for the degree of weathering in the exposure and the method of excavation that was used to make the exposure, i.e. the ‘reference’ rock mass values are not influenced by local influences such as weathering and method of excavation. A new slope can then be designed in the ‘reference’ rock mass with compensation for the damage due to the method of excavation to be used for making the new slope and compensation for deterioration of the rock mass due to future weathering (the ‘slope’ rock mass). If the stability of an already existing slope is assessed the ‘exposure’ and ‘slope’ rock mass values are the same.

The failure mechanisms are divided in orientation dependent and orientation independent. Orientation dependent failure mechanisms depend on the orientation of the slope with respect to the orientation of the discontinuities in the rock mass, i.e. sliding (plane and wedge sliding) and toppling failure. Orientation independent relates to the possibility that a slope fails independently from its orientation, e.g. circular failure completely through newly formed discontinuities in intact rock blocks, or failing partially following existing discontinuities and partially new discontinuities.

In addition the shear strength along a discontinuity ('sliding criterion')^[1][2][3] and 'rock mass cohesion' and 'rock mass friction' can be determined. The system has been used directly or modified in various geology and climate environments throughout the world.^[4][5][6] The system has been modified for slope stability assessment in open pit coal mining.^[7]

References

1. Hack, R. (1996, 1998). Slope Stability Probability Classification (SSPC) (PDF). ITC publication 43. Technical University Delft & Twente University - International Institute for Aerospace Survey and Earth Sciences (ITC Enschede), Netherlands. p. 258. ISBN 90-6164-154-3. Check date values in: |date= (help)
2. Hack, R.; Price, D.; Rengers, N. (2003). "A new approach to rock slope stability – a probability classification (SSPC)". Bulletin of Engineering Geology and the Environment 62 (2): 167–184. doi:10.1007/s10064-002-0155-4 (inactive 2015-02-02).
3. Andrade, P.S.; Saraiva, A.A. (2008). "Estimating the joint roughness coefficient of discontinuities found in metamorphic rocks". Bulletin of Engineering Geology and the Environment 67 (3, number 3): 425–434. doi:10.1007/s10064-008-0151-4.
4. Filipello, A.; Giuliani, A.; Mandrone, G. (2010). "Rock Slopes Failure Susceptibility Analysis: From Remote Sensing Measurements to Geographic Information System Raster Modules". American Journal of Environmental Sciences 6 (6, number 6): 489–494. doi:10.3844/ajessp.2010.489.494.
5. Hailemariam, G.T.; Schneider, J.F. (May 2–7, 2010). "Rock Mass Classification of Karstic Terrain in the Reservoir Slopes of Tekeze Hydropower Project" (PDF). EGU General Assembly 2010. EGU2010-831, 2010. Vienna, Austria. pp. 831–831.
6. Dhakal, S.; Upreti, B.N.; Yoshida, M.; Bhattarai, T.N.; Rai, S.M.; Gajurel, A.P.; Ulak, P.D.; Dahal, R.K. (30 September – 13 October 2004). "Application of the SSPC system in some of the selected slopes along the trekking route from Jomsom to Kagbeni, central-west Nepal". In Yoshida, M.; Upreti, B.N.; Bhattarai, T.N.; Dhakal, S. Natural disaster mitigation and issues on technology transfer in South and Southeast Asia; proceedings of the JICA Regional Seminar. Kathmandu, Nepal: Department of Geology, Tri-Chandra Campus, Tribhuvan University, Kathmandu, Nepal. pp. 79–82. Check date values in: |year= / |date= mismatch (help)
7. Lindsay, P.; Campbellc, R.N.; Fergussonc, D.A.; Gillarda, G.R.; Moore, T.A. (2001). "Slope stability probability classification, Waikato Coal Measures, New Zealand". International Journal of Coal Geology 45 (2–3): 127–145. doi:10.1016/S0166-5162(00)00028-8.

Further reading

• Devoto, S.; Castelli, E. (September 2007). "Slope stability in an old limestone quarry interested by a tourist project". 15th Meeting of the Association of European Geological Societies: Georesources Policy, Management, Environment. Tallinn.
• Douw, W. (2009). Entwicklung einer Anordnung zur Nutzung von Massenschwerebewegungen beim Quarzitabbau im Rheinischen Schiefergebirge. Hackenheim, Germany: ConchBooks. p. 358. ISBN 978-3-939767-10-7.
• Hack, H.R.G.K. (25–28 November 2002). "An evaluation of slope stability classification. Keynote Lecture.". In Dinis da Gama, C.; Ribeira e Sousa, L. Proc. ISRM EUROCK’2002. Funchal, Madeira, Portugal: Sociedade Portuguesa de Geotecnia, Lisboa, Portugal. pp. 3–32. ISBN 972-98781-2-9.
• Liu, Y.-C.; Chen, C.-S. (2005). "A new approach for application of rock mass classification on rock slope stability assessment". Engineering Geology 89: 129–143. doi:10.1016/j.enggeo.2006.09.017.
• Pantelidis, L. (2009). "Rock slope stability assessment through rock mass classification systems". International Journal of Rock Mechanics and Mining Sciences 46 (2, number 2): 315–325. doi:10.1016/j.ijrmms.2008.06.003.
• Rupke, J.; Huisman, M.; Kruse, H.M.G. (2007). "Stability of man-made slopes". Engineering Geology 91 (1): 16–24. doi:10.1016/j.enggeo.2006.12.009.
• Singh, B.; Goel, R.K. (2002). Software for engineering control of landslide and tunnelling hazards 1. Taylor & Francis. p. 358. ISBN 90-5809-360-3.