2024-03-28T13:33:50Z
https://tsukuba.repo.nii.ac.jp/oai
oai:tsukuba.repo.nii.ac.jp:00028951
2022-04-27T08:56:57Z
160:1960
160:2171
3:62:5592:2049
Influence of fine sediment on the fluidity of debris flows
堀田, 紀文
西本, 晴男
Hotta, Norifumi
Kaneko, Takahiro
Iwata, Tomoyuki
Nishimoto, Haruo
Debris flows include a great diversity of grain sizes with inherent features such as inverse grading, particle size segregation, and liquefaction of fine sediment. The liquefaction of fine sediment affects the fluidity of debris flows, although the behavior and influence of fine sediment in debris flows have not been examined sufficiently. This study used flume tests to detect the effect of fine sediment on the fluidity of laboratory debris flows consisting of particles with various diameters. From the experiments, the greatest sediment concentration and flow depth were observed in the debris flows mixed with fine sediment indicating increased flow resistance. The experimental friction coefficient was then compared with the theoretical friction coefficient derived by substituting the experimental values into the constitutive equations for debris flow. The theoretical friction coefficient was obtained from two models with different fine-sediment treatments: assuming that all of the fine sediments were solid particles or that the particles consisted of a fluid phase involving pore water liquefaction. From the comparison of the friction coefficients, a fully liquefaction state was detected for the fine particle mixture. When the mixing ratio and particle size of the fine sediment were different, some other cases were considered to be in a partially liquefied transition state. These results imply that the liquefaction of fine sediment in debris flows was induced not only by the geometric conditions such as particle sizes, but also by the flow conditions.
journal article
Science Press
2013-04
application/pdf
Journal of mountain science
2
10
233
238
http://hdl.handle.net/2241/119171
1672-6316
AA11957323
https://tsukuba.repo.nii.ac.jp/record/28951/files/JMS_10-2.pdf
eng
10.1007/s11629-013-2522-y
© Science Press and Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg 2013 The original publication is available at www.springerlink.com