Analysing the kinematic response to groundwater fluctuations of a slow moving landslide in varved clays, using two alternatives of the equation of motion

Auteurs :
VAN ASCH, T.W.J.
MALET, J.P.

Description :
The landslide analysed, which developed in varved clays, is situated near Monestier-du-Percy, on the «Trièves Plateau» in the French pre-Alps. Two models based on the equation of motion were tested on these displacement profiles in combination with piezometric observations : AC-model (with the complete equation of motion) and NA-model ( a sort of steady state model). It appeared that for slow moving landslides, differences in calculated velocities and displacements between the two models can be neglected for gradual rising and falling groundwater levels. The landslide monitoring did not show a simple linear relation between groundwater level fluctuation and displacement velocity. Back calculation of the viscosity for the various time intervals within a selected test period (1992-1995) shows an exponential relationship between excess shear stress and shear strain rate. It can be explained by a rate dependency of an apparent viscosity or by a rate dependent change in thickness of the shear band. - (NF)


Type de document :
Article de périodique

Source :
Geografia fisica e dinamica quaternaria, issn : 0391-9838, 2011, vol. 34, n°. 1, p. 45-53, nombre de pages : 9, Références bibliographiques : 33 ref.

Date :
2011

Editeur :
Pays édition : Italie, Torino, Comitato glaciologico italiano