Pore pressure response to unloading, progressive slope failure, and the stratigraphic record
Presented by Peter FLEMINGS on 23 Sep 2013 from 14:00 to 14:30
Type: Oral presentation, full-paper
Session: 03: Pore Fluids & Microfabrics
Track: Oral presentations
Pore pressure response during slope failure controls the nature of slope failure, its periodic behavior, and the form of the stratigraphic record. During liquefaction failure, large volumes of sediment associated with clay rich deposits undergo contraction and liquefication during shear failure. Episodic, retrogressive, failures are recorded in densified mass transport deposits that record separate viscous flows. During breaching failure, sand rich deposits undergo dilation. Resultant under-pressures generate near vertical and progressive slope failure. Sediment is released as episodic or steady turbidity flows. I present field observations, and laboratory results to describe these processes and I use poromechanical modeling to describe the coupling between unloading and shear failure. I emphasize how pore pressure dissipation at the failure front controls the episodic nature of these failures.
I present field observations, laboratory results and poromechanical modeling to describe both liquefaction and breaching slope failures. I describe how the coupling between shear and pore pressure controls the form and timescale of the slope failures.