23-25 September 2013
GEOMAR East shore
Europe/Berlin timezone
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How Stable Is the Nice Slope? – An Analysis Based on Strength and Cohesion from Ring Shear Experiments

Presented by Sylvia STEGMANN
Type: Poster presentation
Session: Poster session
Track: Poster presentations

Content

The upper shelf of the landslide-prone Ligurian Margin (Western Mediterranean Sea) off Nice well-known for the 1979 Airport Landslide is a natural laboratory to study preconditioning factors and trigger mechanisms for submarine landslides. For this study low-stress ring shear experiments have been carried out on a variety of sediments from >50 gravity cores to characterise the velocity-dependent frictional behaviour. Mean values of the peak coefficient of friction vary from 0.46 for clay-dominated samples (53 % clay, 46 % silt, 1 %) sand up to 0.76 for coarse-grained sediments (26 % clay, 57 % silt, 17 % sand). The majority of the sediments tested show velocity strengthening regardless of the grain size distribution. For clayey sediments the peak and residual cohesive strength increases with increasing normal stress, with values from 1.3 to 10.6 kPa and up to 25 % of all strength supported by cohesive forces in the shallowmost samples. A pseudo-static slope stability analysis reveals that the different lithologies (even clay-rich material with clay content50 %) tested are stable up to slope angles <26° under quasi-drained conditions.

Place

Location: GEOMAR East shore
Address: Wischhofstr. 1-3 / D-24148 Kiel
Room: Lecture Hall Geb. 8A

Primary authors

  • Sylvia STEGMANN MARUM – Center for Marine Environmental Sciences, Marine Geotechnics, University of Bremen, Germany
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Co-authors

  • Achim KOPF MARUM – Center for Marine Environmental Sciences, Marine Geotechnics, University of Bremen, Germany
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