Are real-world shallow landslides reproducible by physically-based models? Four test cases in the Laternser valley, Vorarlberg (Austria)

Autor(en)

Thomas Zieher, Barbara Schneider-Muntau, Martin Mergili

Abstrakt

In contrast to the complex nature of slope failures, physically-based slope stability models rely on simplified representations of landslide geometry. Depending on the modelling approach, landslide geometry is reduced to a slope-parallel layer of infinite length and width (e.g., the infinite slope stability model), a concatenation of rigid bodies (e.g., Janbu's model), or a 3D representation of the slope failure (e.g., Hovland's model). In this paper, the applicability of four slope stability models is tested at four shallow landslide sites where information on soil material and landslide geometry is available. Soil samples were collected in the field for conducting respective laboratory tests. Landslide geometry was extracted from pre- and post-event digital terrain models derived from airborne laser scanning. Results for fully saturated conditions suggest that a more complex representation of landslide geometry leads to increasingly stable conditions as predicted by the respective models. Using the maximum landslide depth and the median slope angle of the sliding surfaces, the infinite slope stability model correctly predicts slope failures for all test sites. Applying a 2D model for the slope failures, only two test sites are predicted to fail while the two other remain stable. Based on 3D models, none of the slope failures are predicted correctly. The differing results may be explained by the stabilizing effects of cohesion in shallower parts of the landslides. These parts are better represented in models which include a more detailed landslide geometry. Hence, comparing the results of the applied models, the infinite slope stability model generally yields a lower factor of safety due to the overestimation of landslide depth and volume. This simple approach is considered feasible for computing a regional overview of slope stability. For the local scale, more detailed studies including comprehensive material sampling and testing as well as regolith depth measurements are necessary.

Organisation(en)

Institut für Geographie und Regionalforschung

Externe Organisation(en)

Leopold-Franzens-Universität Innsbruck

Journal

Landslides

Band

14

Seiten

2009-2023

Anzahl der Seiten

15

ISSN

1612-510X

DOI

https://doi.org/10.1007/s10346-017-0840-9

Publikationsdatum

12-2017

Peer-reviewed

Ja

ÖFOS 2012

105403 Geoinformatik, 207201 Bodenmechanik, 105404 Geomorphologie, 105902 Naturgefahren

Schlagwörter

ASJC Scopus Sachgebiete

Geotechnical Engineering and Engineering Geology

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/07847305-61f4-408c-a8a3-b471d8e5b74a