Abstract
Dynamic fragmentation is a new hypothesis for the mechanism of rock-avalanche long runout. Low-strain-rate fragmentation is dominated by growth of a few flaws. It is the regime leading to initial failure of many landslides. Static rock strength is largely independent of loading rate. The dynamic regime is entered when growth of a few flaws does not relieve elastic strain fast enough, and stresses rise adjacent to the flaws, forcing many new ones to nucleate and grow. Strengths of dynamically fragmenting materials increase at about the 4th root of strain rate. Elastic strain energy, W, per unit volume, released at failure is given by W=Q²/(2E), where Q is strength and E is elastic modulus. Its explosive release as kinetic energy provides a large, isotropic, clast-dispersing stress, every time any clast is stressed to failure. Fragmentation-induced dilation is a positive granular “pressure”, but also causes low pore-fluid pressure, and is incompatible with saturation of voids by liquids and therefore is incompatible with high pore pressure and undrained loading. Driven entirely by internal deformation within the avalanching mass, dynamic fragmentation propels the distal margins of large avalanches of brittle rock further than they could travel had they just collapsed to joint-bounded clasts.
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References
Abdrakhmatov, K. and Strom, A. (2002) Rockslides and rock avalanches of the central and northern Tien Shan. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 1–6.
Bergstrom, B.H. (1963) Energy and size distribution aspects of single particle crushing. In Fairhurst, C. (ed) Rock Mechanics, Proceedings of the 5th symposium on rock mechanics May 1962. Pergamon Press New York. p. 155–172.
Bieniawski, Z.T. (1967) Mechanism of brittle fracture in rock: Part I—Theory of the fracture process, and Part II— Experimental studies. Int. J. Rock Mech. Min. Sci. 4: 395–423.
Bieniawski, Z.T. (1968) The effect of specimen size on compressive strength of coal. Int. J. Rock Mech. Min. Sci. 5: 325–335.
Chinn, T.J. H. (1975) Late Quaternary snowlines and cirque moraines within the Waimakariri watershed. MSc thesis, University of Canterbury, New Zealand. 213 p.
Cook, N.G.W. (1965) The failure of rock. Int. J. Rock Mech. Min. Sci. 2: 389–403.
Cruden, D.M. and Hungr, O. (1986). The debris of the Frank Slide and theories of rockslide-avalanche mobility. Can. J. Earth Sci. 23, 425–432.
Davies, T.R. and McSaveney, M.J. (1999) Runout of dry granular avalanches. Can. Geotech. J. 36, 313–320.
Davies, T.R. and McSaveney, M.J. (2002) Dynamic simulation of the motion of fragmenting rock avalanches. Can. Geotech. J. 39, 789–798.
Davies, T.R., McSaveney, M.J. and Hodgson, K.A. (1999) A fragmentation-spreading model for long-runout rock avalanches. Can. Geotech. J. 36, 1096–1110.
Dawson, R.F., Morgenstern, N.R and Stokes, A.W. (1998) Liquefaction flowslides in Rocky Mountain coal waste dumps. Can. Geotech. J. 35, 328–343.
Fraser, H.J., (1935) Experimental study of the porosity and permeability of clastic sediments. J. Geol. 43, 910–1010.
Glicken, H. (1996) Rockslide-debris avalanche of May 18, 1980, Mount St. Helens volcano, Washington. U.S. Dept of the Interior, U.S. Geol. Surv. Open-file Report 96–677. 90 p.
Grady, M.E. and Kipp, D.E. (1987) Dynamic rock fragmentation. In Atkinson, B.K. (ed) Fracture mechanics of rock. Academic Press, London, p. 429–475.
Heim, A. (1882) Der Bergsturz von Elm. Z. Deut Geol. Gesell. 34, 74–115.
Herget, G. (1988) Stresses in rock. Balkema, Rotterdam.179 p.
Hewitt, K., (2002) Diagnostics for field identification of rock avalanches involving complex run out and emplacement, with examples from the Karakorum Himalaya. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 57–61.
Hudson, J.A., Crouch, S.L. and Fairhurst, C. (1972) Soft, stiff and servo-controlled testing machines: a review with reference to rock failure. Eng. Geol. 6: 155–189.
Hungr, O. (2002) Rock avalanche motion: process and modelling. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 66–69.
Hutchinson, J.N. (2002) Chalk flows from the coastal cliffs of north west Europe. In Evans, S.G. and Degraff, J.V. (eds) Catastrophic landslides: occurrence, mechanisms and mobility. Boulder, Colorado. Geological Society of America Reviews in Engineering Geology 15, 257–302.
Hutchinson, J.N. and Bhandari, R.K. (1971) Undrained loading, a fundamental mechanism of mudflows and other mass movements. Geotechnique 21, 253–358.
Iverson, R.M. (2002) Modelling the dynamics of rock and debris avalanches. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 77–81.
Legros, F. (2002) The mobility of long-runout landslides. Eng. Geol. 63, 301–331.
Mamaev, Y.A., (2002) Development and structure of “Usoi” landslide-collapse damming, Murgab River valley, Pamirs. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 87–88.
McGarr, A. (1997) A mechanism for high wall-rock velocities in rockbursts. Pure and Applied Geophys. 150,381–391.
McSaveney, M.J. (2002) Recent rockfalls and rock avalanches in Mount Cook National Park, New Zealand. In Evans, S.G. and Degraff, J.V. (eds) Catastrophic landslides: occurrence, mechanisms and mobility. Boulder, Colorado. Geol. Soc. Am. Reviews in Engineering Geology 15, 35–71.
McSaveney, M. and Davies, T. (2002) Rapid rock-mass flow with dynamic fragmentation. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 89–92.
McSaveney, M.J., Davies, T.R. and Hodgson, K.A., (2000) A Contrast in style between large and small rock avalanches. In Bromhead, E., Dixon, N., and Ibsen, M.-L. (eds). Landslides in research, theory and practice Vol. 2. Proceedings of the 8th International Symposium on Landslides, Cardiff, 26–30 June 2000. Thomas Telford, London, p. 1051–1058.
Melosh, H.J., Ryan, E.V. and Asphaug, E. (1992) Dynamic fragmentation in impacts: hydrocode simulation of laboratory impacts. J. Geophys. Res. 97, 14,735–14,759.
Pollet, N. (2000) Un exemple de sédimentation gravitaire événementielle en domaine continental: le sturzströms Holocène de Films (Grisons, Alpes suisses). Faciès, fabrique interne et méchanismes. Mémoire de DEA, Université de Lille, 50 p.
Strom, A. (2002) Morphology and internal structure of rockslides and rock avalanches: grounds and constraints for their modelling. In Evans, S.G. and Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p 140–145.
Wassmer, P., Schneider, J-L. and Pollet, N. (2002a) The “playing cards” model as a tool to better understanding long run-out: the case of the Flims Holocene Sturzstrom. In Evans, S.G., Martino, S. (eds) Abstract volume, NATO Advanced Research Workshop: Massive rock slope failure: New models for hazard assessment. Celano, Italy, June 16–21, 2002. p. 152–155.
Wassmer, P., Schneider, J-L. and Pollet, N. (2002b) Internal structure of huge mass movements: a key to a better understanding of long runout - the multi-slab theoretical model. Proceedings of the international symposium on Landslide risk, mitigation and protection of cultural and natural heritage. 21–25 January 2002, Kyoto, Japan.
Wawersik, W.R. and Fairhurst, C. (1970) A study of brittle rock fracture in laboratory compression experiments. Int. J. Rock Mech. Min. Sci. 7: 561–575.
Wright, C.A. (1998) The AD 930 Long-runout Round Top debris avalanche, Westland. N. Z. J. Geol. and Geophys. 41, 493–497.
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McSAVENEY, M., DAVIES, T. (2006). INFERENCES FROM THE MORPHOLOGY AND INTERNAL STRUCTURE OF ROCKSLIDES AND ROCK AVALANCHES RAPID ROCK MASS FLOW WITH DYNAMIC FRAGMENTATION:. In: Evans, S.G., Mugnozza, G.S., Strom, A., Hermanns, R.L. (eds) Landslides from Massive Rock Slope Failure. NATO Science Series, vol 49. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-4037-5_16
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