@article{PAR00006224,
  title = {{P}ore fluid pressure and internal kinematics of gravitational laboratory air-particle flows : insights into the emplacement dynamics of pyroclastic flows},
  author = {{R}oche, {O}livier and {M}ontserrat, {S}. and {N}ino, {Y}. and {T}amburrino, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he emplacement dynamics of pyroclastic flows were investigated through noninvasive measurements of the pore fluid pressure in laboratory air-particle flows generated from the release of fluidized and nonfluidized granular columns. {A}nalyses of high-speed videos allowed for correlation of the pressure signal with the flow structure. {T}he flows consisted of a sliding head that caused underpressure relative to the ambient, followed by a body that generated overpressure and at the base of which a deposit aggraded. {F}or initially fluidized flows, overpressure in the body derived from advection of the pore pressure generated in the initial column and decreased by diffusion during propagation. {R}elatively slow diffusion caused the pore pressure in the thinner flow to be larger than lithostatic at early stages. {F}urthermore, partial auto-fluidization, revealed in initially nonfluidized flows, also occurred and contributed to maintain high pore pressure, whereas dilation or contraction of the air-particle mixture with associated drag and/or pore volume variation transiently led the pressure to decrease or increase, respectively. {T}he combination of all these processes resulted in long-lived high pore fluid pressure in the body of the flows during most of their emplacement. {I}n the case of the initially fluidized and slightly expanded (similar to 3-4%) flows, (at least) similar to 70%-100% of the weight of the particles was supported by pore pressure, which is consistent with their inertial fluid-like behavior. {D}ense pyroclastic flows on subhorizontal slopes are expected to propagate as inertial fluidized gas-particle mixtures consisting of a sliding head, possibly entraining basement-derived clasts, and of a gradually depositing body.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch.{S}olid {E}arth},
  volume = {115},
  numero = {},
  pages = {{B}09206},
  ISSN = {0148-0227},
  year = {2010},
  DOI = {10.1029/2009jb007133},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00006224},
}