A two-fluid model for avalanche and debris flows

E. Bruce Pitman, Long Le
2005 Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences  
Geophysical mass flows -debris flows, avalanches, landslides -are often initiated by volcanic activity. These flows can contain O(10 6 −10 10 ) m 3 or more of material. Typically this material is a mixture of soil and rocks in the centimeter size range, sometimes mixed with meter-sized boulders. These flows can be O(10) − O(100) m deep and can run out over tens of kilometers. And often these flows contain a significant quantity of interstitial fluid. The range of scales, the rheology of this
more » ... , muddy mess, the motion of the pore fluid, the difficulty of representing a free surface flow, all make these mass flows a complex modeling and computational problem. We lack a full understanding of how mass flows are initiated. But there is a growing body of modeling and computational research yielding insight to the flow process, once motion begins. This paper describes one model of these flows. This model uses as its starting point the volume averaged solids-fluid equations common in fluids and engineering research. Phenomenological modeling and the process of depth averaging combine to yield a tractable set of equations.
doi:10.1098/rsta.2005.1596 pmid:16011934 fatcat:dih76h7r3fhyvmvpecmrdzhq2i