Seismic triggering of landslides. Part B: Simulation of dynamic failure processes
- 1GeomaC-LGIH, University of Liege, B52, 4000 Sart Tilman – Liege, Belgium
- 2Institute of the Dynamics of the Geosphere, Leninsky Avenue, 119334 Moscow, Russia
- 3Dipartimento di Ingegneria Strutturale, Politecnico di Milano, Pzza. Leonardo da Vinci 32, 20133 Milano, Italy
- 4LIRIGM, Université Joseph Fourier Grenoble, BP53, 38041 Grenoble cedex 9, France
Abstract. From field observations it is possible to establish correlations between geological conditions and landslide occurrence. However, in general, it is difficult to assess the affect of individual factors on slope instability because of their mutual interaction. In addition, the dynamic effect of propagating seismic waves significantly increases the complexity of the slope stability problem. Wave diffraction, reflection and focusing effects are dependent on local geological conditions and make it difficult to analyse dynamic sliding mechanisms using field observations alone. As a consequence, in order to examine the influence of various geological and seismic factors on slope movements, it is often necessary to produce numerical models. This paper describes the results of such models as applied to two case studies in Kyrgyzstan: the Ananevo rockslide, located in granite, and the Suusamyr debris slump-flow, situated within soft sediments (see Part A: Havenith et al., 2003). Discrete element modelling (UDEC), adapted both to the discontinuous character of fractured rock and to the heterogeneity of layered mediums, was used. This permitted simulation of deformation mechanisms, including seismically induced bending, block tilting, and slip. Particular attention was paid to the interaction between deformation mechanisms, site-specific amplification effects, and subsurface structure.