Factors influencing granular debris flow behaviour: An experimental investigation
- Conference Paper
Granular debris flows represent a significant hazard in mountainous regions. However the influence of flow velocity and geometry and of constituent materials upon runout behaviour is still a matter of debate. Granular debris flow mechanics were investigated experimentally using a debris flow flume. High speed imaging of the flow through a Perspex window allowed flow mechanisms to be examined in conjunction with the final runout behaviour. The influence of particle size and the role of fines were examined by varying individual size ranges. The mobility of fully saturated flows was found to be a function of relative density, taking into account both water content and particle size distribution. For the same water content, increasing the large particle content tended to result in a lower relative density and hence a more mobile flow due to fewer particle contacts. However, the presence of very large particles (where large particle diameter is roughly equal to the flow depth) appeared alter the flow surge behaviour. Where erodible beds were investigated, local topography was found to influence f low velocity and entrainment of bed debris. Greater bed entrainment and runout was mostly observed where the bed was more saturated and more uneven, although this was not universal. Bed saturation was found to be a function of the small particle content, with greater water retention (and erosion) for beds with greater fines. This suggests competing issues with respect to particle size that may explain the divergent results from field and laboratory tests on debris flows. © 2006 Taylor & Francis Group, London. Show more
Book titlePhysical Modelling in Geotechnics
Journal / seriesBalkema - Proceedings and Monographs in Engineering, Water and Earth Sciences
Pages / Article No.
PublisherTaylor & Francis
Organisational unit03474 - Springman, Sarah M. / Springman, Sarah M.
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