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USGS · 70020072

Geotechnical properties of debris-flow sediments and slurries

J. J. Major·R.M. Iverson·D.F. McTigue·S. Macias·B.K. Fiedorowicz
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Abstract

Measurements of geotechnical properties of various poorly sorted debris-flow sediments and slurries (??? 32 mm diameter) emphasize their granular nature, and reveal that properties of slurries can differ significantly from those of compacted sediments. Measurements show that: (1) cohesion probably offers little resistance to shear in most debris flows under low confining stresses normally found in nature; (2) intrinsic hydraulic permeabilities of compacted debris-flow sediments vary from about 10-14-10-9 m2; permeabilities of 'typical' debris-flow slurries fall toward the low end of the range; (3) debris-flow slurries are characterized by very large values of 'elastic' compressibility (C approx. 10-2 kPa-1); and (4) hydraulic diffusivities of quasistatically consolidating slurries are approx. 10-4-10-7 m2/s. Low hydraulic diffusivity of debris slurries permits excess fluid pressure and low effective strength to persist during sediment transport and deposition.

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J. J. Major, R.M. Iverson, D.F. McTigue, S. Macias, B.K. Fiedorowicz. 1997. Geotechnical properties of debris-flow sediments and slurries. https://pubs.usgs.gov/publication/70020072

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