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

Year 2023, , 142 - 165, 24.08.2023

Mehmet Celal Tunusluoğlu

https://doi.org/10.17824/yerbilimleri.1281981

Abstract

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.

Keywords

Landslide, Non-circular failure, Back analysis, Slope stability, Guzelyali (Canakkale)

Thanks

The author would like to express their gratitude to the municipality of Canakkale for information and the logs of geotechnical boreholes.

Bir Şev Duraysızlığının Mühendislik Jeolojisi Değerlendirmesi: Güzelyalı Bölgesinde Bir Vaka Çalışması (Çanakkale, Türkiye)

Abstract

Güzelyalı köyü, Çanakkale şehirinin 20 km güneybatısında, Çanakkale Boğazı kıyında yer almaktadır. Güzelyalı köyünün girişinde yer alan yerleşim alanında Kasım 2001 tarihinden itibaren farklı zamanlarda heyelanlar yaşanmıştır. Şubat 2013’te, Güzelyalı heyelanı şiddetli yağış nedeniyle tekrar tetiklenmiştir. Heyelan sonucu binalarda, bahçe duvarlarında ve Çanakkale-Güzelyalı yolunda deformasyonlar ve çatlaklar oluşmuştur. Bu çalışmada, Güzelyalı heyelanına neden olan kayma yüzeyinin derinliği ve birimlerin jeoteknik özellikleri belirlenerek heyelanların önlenmesi için en uygun iyileştirme yönteminin belirlenmesi amaçlanmıştır. Bu amaçla, duraysızlığın değerlendirilmesi amacıyla arazi gözlemleri, sondaj çalışmaları, sondaj çalışmaları ile indeks ve mekanik testler için örnek alma ve inklinometre kullanılarak izleme çalışmaları yapılmıştır. İnklinometre ölçümleri sonucunda heyelanın yer değiştirme hızı genel olarak 2,5-63,5 cm/yıl olarak belirlenmiş olup heyelanın çok yavaş hareket ettiğini göstermektedir. Ayrıca, limit denge yöntemi ve sonlu elemanlar yöntemi kullanılarak şev stabilitesi analizleri yapılmıştır. Yenilme anında yenilme yüzeyi boyunca makaslama dayanımı parametrelerini belirlemek için, heyelan hareketi yönünde dairesel olmayan yenilme modelleri için Janbu modeline dayalı olarak geriye dönük analizler yapılmıştır. Ayrıca, heyelan bölgesinde şev yüzeyinde drenaj sistemlerinin kurulması önerilmiştir. Ancak stabilite analizleri ve heyelan bölgesindeki arazi kullanımı dikkate alındığında mikro kazıklarla iyileştirmenin güvenilir ve ekonomik bir iyileştirme yöntemi olacağı düşünülmektedir.

Keywords

Heyelan, Dairesel olmayan yenilme, Geriye dönük analiz, Şev stabilitesi, Güzelyalı (Çanakkale)

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