TY  - JOUR
A1  - McArdell, Brian W.
A1  - Bartelt, Perry
A1  - Kowalski, Julia
T1  - Field observations of basal forces and fluid pore pressure in a debris flow
T2  - Geophysical Research Letters (GRL)
N2  - Using results from an 8 m2 instrumented force plate we describe field measurements of normal and shear stresses, and fluid pore pressure for a debris flow. The flow depth increased from 0.1 to 1 m within the first 12 s of flow front arrival, remained relatively constant until 100 s, and then gradually decreased to 0.5 m by 600 s. Normal and shear stresses and pore fluid pressure varied in-phase with the flow depth. Calculated bulk densities are ρb = 2000–2250 kg m−3 for the bulk flow and ρf = 1600–1750 kg m−3 for the fluid phase. The ratio of effective normal stress to shear stress yields a Coulomb basal friction angle of ϕ = 26° at the flow front. We did not find a strong correlation between the degree of agitation in the flow, estimated using the signal from a geophone on the force plate, and an assumed dynamic pore fluid pressure. Our data support the idea that excess pore-fluid pressures are long lived in debris flows and therefore contribute to their unusual mobility.
KW  - debris flow
Y1  - 2007
UR  - https://opus.bibliothek.fh-aachen.de/opus4/frontdoor/index/index/docId/5010
SN  - 0094-8276
VL  - 34
IS  - 7
ER  -