This paper deals with the analysis of deformation behavior of a slow movement in a complex rock formation (Marly-Arenaceous Formation). The time history of displacements measured in the last 20 years shows that the ongoing deformation process is essentially a stationary creep phenomenon, also influenced by transient variations in pore pressure distribution. The movement was recognized after the discovery of intense cracking in the concrete lining of a hydraulic tunnel running across the slope, which will serve for water diversion from a rockfill dam, not yet in operation, located adjacent to the moving mass. Field investigations strongly suggest the ongoing movement takes place along a basal slip surface, formed by a tectonized clay rich interbed, with mobilized friction angle close to residual. The influence of reservoir level increase on the slope displacement and mobilized friction angle of the slip surface has been highlighted. The observed slope movement has been studied by employing viscoplastic model in 2D plane strain analyses (FLAC code). The steady state movement can be predicted reasonably using the model. Some creep analyses, carried out considering also the proposed stabilizing embankment at the toe of the slope have shown a substantial decrease in horizontal displacement velocity.

Assefa, S.M., Graziani, A., LEMBO FAZIO, A. (2016). Investigation on a slope movement in a complex rock formation: Modeling of the deformation mode and remedial measures. In 50th US Rock Mechanics / Geomechanics Symposium 2016 (pp.167-176). American Rock Mechanics Association (ARMA).

Investigation on a slope movement in a complex rock formation: Modeling of the deformation mode and remedial measures

ASSEFA, SIRAJ MULUGETA;GRAZIANI, ALESSANDRO;LEMBO FAZIO, Albino
2016

Abstract

This paper deals with the analysis of deformation behavior of a slow movement in a complex rock formation (Marly-Arenaceous Formation). The time history of displacements measured in the last 20 years shows that the ongoing deformation process is essentially a stationary creep phenomenon, also influenced by transient variations in pore pressure distribution. The movement was recognized after the discovery of intense cracking in the concrete lining of a hydraulic tunnel running across the slope, which will serve for water diversion from a rockfill dam, not yet in operation, located adjacent to the moving mass. Field investigations strongly suggest the ongoing movement takes place along a basal slip surface, formed by a tectonized clay rich interbed, with mobilized friction angle close to residual. The influence of reservoir level increase on the slope displacement and mobilized friction angle of the slip surface has been highlighted. The observed slope movement has been studied by employing viscoplastic model in 2D plane strain analyses (FLAC code). The steady state movement can be predicted reasonably using the model. Some creep analyses, carried out considering also the proposed stabilizing embankment at the toe of the slope have shown a substantial decrease in horizontal displacement velocity.
9781510828025
Assefa, S.M., Graziani, A., LEMBO FAZIO, A. (2016). Investigation on a slope movement in a complex rock formation: Modeling of the deformation mode and remedial measures. In 50th US Rock Mechanics / Geomechanics Symposium 2016 (pp.167-176). American Rock Mechanics Association (ARMA).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/317024
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