Near-surface geophysical methods for investigating the Buyukcekmece landslide in Istanbul, Turkey

Autor: Esref Yalcinkaya, Luca Lenti, Oguz Ozel, Salvatore Martino, Ethem Görgün, Céline Bourdeau, Pascal Bigarre, Hakan Alp, Stella Coccia
Přispěvatelé: Istanbul University, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Séismes et Vibrations (IFSTTAR/GERS/SV), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Sols, Roches et Ouvrages Géotechniques (IFSTTAR/GERS/SRO), Ecole Nationale Supérieure des Mines de Nancy (ENSMN), Université de Lorraine (UL)-Institut Mines-Télécom [Paris] (IMT), Institut National de l'Environnement Industriel et des Risques (INERIS), EC/FP7/308417/EU/New Directions in Seismic Hazard assessment through Focused Earth Observation in the Marmara Supersite/MARSITE
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Journal of Applied Geophysics
Journal of Applied Geophysics, Elsevier, 2016, 134, pp. 23-35. ⟨10.1016/j.jappgeo.2016.08.012⟩
ISSN: 0926-9851
DOI: 10.1016/j.jappgeo.2016.08.012⟩
Popis: In this study, near-surface geophysical techniques are used to investigate the physical characteristics of the Buyukcekmece landslide (Istanbul, Turkey). The Buyukcekmece landslide has continuous activity at a low velocity and is classified as a complex mechanism. It includes rototranslational parts, several secondary scarps, several landslide terraces, and evidence of two earth flows. It mainly develops in the clayey layers of the Danismen Formation. According to our findings, P-wave velocities ranging from 300 m/s to 2400 m/s do not provide notable discrimination between sliding mass and stable soil. They show variations in blocks reflecting a complex structure. We obtained the S-wave velocity structure of the landslide up to 80 m by combining the analysis of MASW and ReMi. It is clear that S-wave velocities are lower in the landslide compared to those of the stable area. Identical S-wave velocities for the entire area at depths higher than 60 m may point out the maximum thickness of the landslide mass. Resonance frequencies obtained from the H/V analysis of the landslide area are generally higher than those of the stable area. The depths computed by using an empirical relationship between the resonance frequency and the soil thickness point out the failure surfaces from 10 to 50 m moving downslope from the landslide crown area. The resistivity values within the landslide are generally lower than 30 Ω m, i.e., a typical value for remolded clayey debris. The geophysical results reflect an overview of the geological model, but the complexity of the landslide makes it difficult to map the landslide structure in detail.
Databáze: OpenAIRE