Modeling the effect of sediment concentration on the flow-like behavior of natural debris flow  

作　　者：Leonardo Schippa 

机构地区：[1]Department of Engineering,University of Ferrara,1 Via Saragat,Ferrara,44122,Italy

出　　处：《International Journal of Sediment Research》2020年第4期315-327,共13页国际泥沙研究（英文版）

摘　　要：The rheological behavior of natural slurries consisting of fine-grained,reconstituted debris-flow deposits on pyroclastic terrains having different solid concentrations(ranging from 30 to 42%)has been investigated using a rotational rheometer equipped with a vane rotor system.Experiments were done by increasing the applied shear stress step by step;then a decreasing stress ramp was applied following the same shear stress levels.The slurry mixtures exhibit a typical yield-stress fluid behavior with a static yield stress larger than the dynamic yield stress.In the range of the shear rate corresponding to the flowlike behavior the slurry mixtures behave as a dilatant fluid at lower grain concentrations and as a pseudoplastic fluid in correspondence with the higher grain content,showing a strong discrepancy from the Bingham idealization.The rheological behavior is better interpreted by a Herschel-Bulkley model,whose rheological parameters strongly depend on the granular concentration.Therefore,a generalized Herschel-Bulkley model accounting for the bulk sediment concentration effect is proposed.

关 键 词：DEBRIS FLOW RHEOLOGY GRAIN CONCENTRATION Herschel-Bulkley model 

分 类 号：P642.23[天文地球—工程地质学]