In Western-Atakent (İstanbul), population density is increasing day by day and settlement areas are expanding. Soil properties and landslide conditions of these expanding regions must be absolutely examined. In the geophysics, there are many methods used to investigate landslide risks and geotechnical structure. The most common geophysical methods used for this purpose are the Electrical resistivity tomography (ERT), Multi-channel Analysis of Surface Waves (MASW) and Microtremor Survey Method (MSM) methods. These methods are very successful techniques for defining underground layers as geological structures, stratigraphic elements, soil layer thickness and landslide. Because of that reason in this study, soil properties and possibility of landslides of the Western-Atakent (İstanbul) region were investigated by using ERT, MASW, MSM and drilling methods. In this study the first stage, electrical resistivity data have been measured using dipole-dipole method on two profiles for ERT. In the second stage, MASW measurements have been made at 25 points on 5 seismic profiles in the field. In the third stage, MSM measurements have been made to determine the fundamental period in the 5-measure station in the study area. In the fourth and final stage, 10-pieces boreholes with a depth of 20 m were drilled to reveal the lithological structure of the study area. As a result of the evaluation of all data, parts of the region that could form landslides were revealed.

ÖZBu çalışmada, İstanbul-Atakent bölgesinde daha sonra yapılması planlanan mühendislik yapıları öncesi, zemin özellikleri ve yer hareketleri nedeniyle doğabilecek olan problemlere karşı alınması gereken tedbirler amacıyla yer altı yapılarının modellenme çalışması gerçekleştirilmiştir. Sondaj kuyularından elde edilen malzeme bilgileri ve litolojik kesit doğrultuları Ceylan Formasyonu, Danişmen Formasyonu ve Çekmece Formasyonu üzerindedir. Çalışmalarda jeofizik yöntemlerden çoklu elektrot yöntemi ile çok kanallı yüzey dalgası analizi (MASW) yöntemi uygulanmıştır ve elde edilen sonuçlar sondaj kesitleri ile karşılaştırılmıştır. Jeofizik yöntemlerden elde edilen özdirenç değişimleri, sismik ortamlar ve mevcut topografyada varlığı görülen derelerin izleri 2B ve 3B grafiklerde işaretlenmiştir. Tüm sonuçların uyum içerisinde olduğunun tespitinden sonra inceleme sahasının yeraltı modellemesi yapılmıştır. İstanbul-Atakent region (the western portion) the underground investıgation and modelling ABSTRACTIn study, the prior engineering structures planned to be done later in İstanbul-Atakent region, a modeling study of underground structures has been carried out for the purpose of to be taken against the problems that may arise due to soil properties and ground movements. Material information obtained from drilling wells and line sections are on the Ceylan Formation, Danişmen Formation and Çekmece Formation. Multiple electrode method from geophysical methods and Multi-channel surface wave analysis methods were used in the studies and obtained results were compared with the drilling sections. The resistivity changes obtained from geophysical methods, traces of seismic environments and existing skies of existing topography, it is marked in 2D and 3D graphics. Underground modeling of the examination area was made, after the determination that all the results are in accordance.