Engineering Geological Assessment of a Slope Instability: A Case Study in the Guzelyali Region (Canakkale, Turkey)

Guzelyali village, 20 km southwest of Canakkale city, is located on the shore of the Canakkale Strait (Dardanelles). The residential area located at the entrance to Guzelyali village has experienced landslides at different times since November 2001. In February 2013, the Güzelyalı landslide was triggered again due to severe rainstorms. As a result of the landslide, deformations and cracks formed in buildings, garden walls and the Canakkale-Guzelyali road. In this study, the aim was to determine the most appropriate improvement method to prevent landslides by determining the depth of the slip surface that caused the Guzelyali landslide and the geotechnical properties of the units. For this purpose, field observations, drilling, obtaining appropriate samples from these works for index and mechanical tests and monitoring studies by using inclinometers were carried out in order to evaluate the instability. As a result of inclinometer measurements, the displacement speed of the landslide was generally determined as 2.5-63.5 cm/year, indicating the landslide moves very slowly. In addition, slope stability analyses were carried out using the limit equilibrium and the finite element methods. To determine the shear strength parameters along the failure surface at the time of the failure, back analyses were performed based on the Janbu model for non-circular failure models in the direction of the landslide movement. It was also proposed to establish drainage systems on slope’s surface in the landslide area. However, considering the stability analysis and the land use in the landslide area, it is considered that remediation using micro piles will be a reliable and economical remediation method. © 2023, Hacettepe Universitesi Yerbilmleri. All rights reserved.