Investigation of Koyulhisar (Sivas) settlement area in terms of slope instability

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2009

Öğrenci: OLGUN HATİBOĞLU

Danışman: TAMER TOPAL

Özet:

Koyulhisar settlement area is located on the northern flank of Kelkit valley which is seismically active and landslide-prone area. The settlement area was adversely affected from active landslides and some of the houses were evacuated. The purpose of this thesis is to delineate areas where slope instability exists within the Koyulhisar settlement area, and to investigate an active landslide by means of field observations, drilling, sampling, field and laboratory testing, and in-situ monitoring using inclinometer. Based on the field studies, it is observed that flyschoidal sequence as bedrock and colluvium consisting clay and silt with some gravel are the main lithological units exposed in the study area. Two landslide affected areas are identified, the one investigated due to its adverse effect to some important governmental buildings, has a non-circular failure surface due to the existence of the flyschoidal sequence below the colluvium. The inclinometer measurements reveal that the displacements are local and their velocities are generally less than 14 mm/year indicating that the landslide is an extremely slow landslide. In addition, high groundwater table is observed as one of the major parameters in occurrence of landslide.