Integrated engineering-geological and numerical approach applied to the large Buyukcekmece (Turkey) landslide for evaluating earthquake-induced effects

Abstract

The Buyukcekmece landslide, W of Istanbul (Turkey), was selected for MARSite project (New directions in seismic hazard assessment through focused Earth observation in the Marmara Super-site) as case-study of earthquake-induced landslides. The local seismic response of the landslide slope was analyzed reconstructing a detailed engineering-geological model. Geophysical measurements were carried out to constrain geometries and attribute mechanical properties. A multisensor in-hole monitoring system and a local GPS-RTK network were installed since October 2014. The collected records show piezometer trends related to seasonal as well to intense rainfalls and confirm a continuous EW movement of the landslide; 65 recorded earthquakes demonstrate an amplification due to the landslide mass. Slope stability was analyzed through an unconventional pseudostatic approach by considering different seismic waveforms. Stress-strain numerical models indicate that local seismic response is jointed to the geological setting and the interaction between seismic waves and slope is not negligible to evaluate possible landslide reactivations.