Iverson, Richard M.; LaHusen, Richard G. 1993. Friction in debris flows: inferences from large-scale flume experiments. In: Shen, Hsieh Wen; Su, S. T.; Wen, Feng, eds. Hydraulic Engineering, Proceedings of 1993 Conference; San Francisco, CA. New York, NY : American Society of Civil Engineers: 2: 1604-1609.
A recently constructed flume, 95 m long and 2 m wide, permits systematicexperimentation with unsteady, nonuniform flows of poorly sorted geologicaldebris. Preliminary experiments with water-saturated mixtures of sand andgravel show that they flow in a manner consistent with Coulomb frictionalbehavior. The Coulomb flow model of Savage and Hutter (1989, 1991), modifiedto include quasi-static pore-pressure effects, predicts flow-front velocities andflow depths reasonably well. Moreover, simple scaling analyses show that grainfriction, rather than liquid viscosity or grain collisions, probably dominates shearresistance and momentum transport in the experimental flows. The same scalingindicates that grain friction is also important in many natural debris flows.