Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic)

• Main Authors: Baron, I., Agliardi, F., Ambrosi, C., Crosta, G. B.
• Other Authors: Czech Geological Survey Praha, Department of Geological Sciences Brno, Faculty of Science Brno (SCI / MUNI), Masaryk University Brno (MUNI)-Masaryk University Brno (MUNI), Dept. of Geological Sciences and Geotechnology, Faculty of Mathematical
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; permafrost
• Online Access: https://hal.archives-ouvertes.fr/hal-00299189; https://hal.archives-ouvertes.fr/hal-00299189/document; https://hal.archives-ouvertes.fr/hal-00299189/file/nhess-5-367-2005.pdf

International audience Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM) of continua (Flac 4.0). We confirmed that such large mass movements could be triggered by water saturation of the bedrock in the three particular geological and geomorphic settings. Such situation could have been caused by heavy rainfalls in humid phases of the Holocene or permafrost melting in Late Glacial. The effects of faulting, very deep weathering of the bedrock, low geotechnical parameters of smectite-rich material and the local slope geometry have also been accounted for in numerical models, as well as the other triggering factors of slope instability. FDM modelled shear zones are in agreement with observations.