Geotechnical Investigation of the Slope Instability in the Gündoğan Village Settlement Area (Ardeşen-Rize)

In the scope of this study, the slope stability problem in the Gündoğan (Ardeşen-Rize) village settlement area covering approximately 2.24 hectares was investigated by means of geotechnical way. The studies were performed in three stages as field, laboratory works and slope stability analyses. For this purpose, along the three survey lines; six boreholes with a total of 150 meters in length were drilled, geophysical studies were performed along the three lines and inclinometer measurements were taken in two boreholes. At the end of the field work, it was determined that the talus whose thickness varies between 5.0 and 16.5 meters overlies the parent material that was formed by the Late Cretaceous-aged Çağlayan Formation consisting of volcano-sedimentary rocks. To determine the physico-mechanical properties of the talus, undisturbed samples were taken from boreholes. Limit equilibrium and the Finite Element based Shear Strength Reduction (FEM-SSR) methods were used to perform stability analyses using the obtained data from field and laboratory studies and the results were compared. When examining the distribution of the failure surfaces obtained from the stability analyses, it was detected that the failure may continue as retrogressive type if there is not any precaution taken on the slope. Performed inclinometer measurements and stability analyses showed that the talus in the Gündoğan village settlement area is unstable and has a landslide potential.