@article{fdi:010076529,
  title = {{C}ontinuum modeling of pressure-balanced and fluidized granular flows in 2-{D} : comparison with glass bead experiments and implications for concentrated pyroclastic density currents},
  author = {{B}reard, {E}. {C}. {P}. and {D}ufek, {J}. and {R}oche, {O}livier},
  editor = {},
  language = {{ENG}},
  abstract = {{G}ranular flows are found across multiple geophysical environments and include pyroclastic density currents, debris flows, and avalanches, among others. {T}he key to describing transport of these hazardous flows is the rheology of these complex multiphase mixtures. {H}ere we use the multiphase model {MFIX} in 2-{D} for concentrated currents to examine the implications of rheological assumptions and validate this approach through comparison to experiments of both frictional and fluidized flows made of glass beads ({S}auter mean grain-size of 75 mu m). {B}ecause the rheology of highly polydisperse, highly angular, polydensity granular mixtures is poorly known, we focus on simplified monodisperse or bidisperse mixtures described by the frictional flow theory of {S}chaeffer (1987, ) and {S}rivastava-{S}undaresan, often referred to as the {P}rinceton model ({S}rivastava & {S}undaresan, 2003, ). {W}e show that simulations including the latter model replicate well the flow shape, kinematics, and pore fluid pressure that match well-constrained dam-break experiments of initially fluidized or pressure-balanced granular flows. {S}imulations reveal that pore fluid pressure is intrinsically modulated by dilation and compaction of the flow and hence can be generated in concentrated pyroclastic density currents. {W}e use these simulations to interpret basal pore pressure signals from local flow properties (mixture density, solid velocity, and pore fluid pressure). {R}heological changes retard these simulated flows considerably near the predicted runout, but most continuum models cannot inherently predict a zero velocity. {W}e suggest an inertial number parameter that can be used to approximate deposition, and this approach could be a valuable tool used to validate simulations against natural pyroclastic current examples.},
  keywords = {granular flows ; pore fluid pressure ; rheology ; pyroclastic density ; currents ; frictional stresses ; multiphase modeling},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {S}olid {E}arth},
  volume = {124},
  numero = {6},
  pages = {5557--5583},
  ISSN = {2169-9313},
  year = {2019},
  DOI = {10.1029/2018jb016874},
  URL = {https://www.documentation.ird.fr/hor/fdi:010076529},
}