Investigation of the soil structure of the area between Yedikule to Sirkeci (Istanbul) using PS logging and earthquake data

Abstract

Marmara Region is located in northwestern Turkey, and the average elevation is of the least. Despite the small size of the region population, its density is above the average of Turkey. The North Anatolian Fault Zone (NAFZ) passing through this region is a fracture that can be observed clearly in its structural characteristics. This region is one of the very active regions in terms of seismic activity when viewed in the historical process. For this reason, earthquake risk analysis is very important for urban planning, construction and major engineering projects such as. Istanbul Metro. This engineering project, which has a worldwide design, has a length of 76 km. Not only it connects Asia and Europe with railways, but also provides urban transportation in a fast and convenient way. In this study, the part of the. Istanbul Metro between Yedikule and Sirkeci on the European continent is investigated. Numerous boreholes were opened in this project line, but here 7 of the best representatives of the region were selected and examined in this study. These boreholes have a depth of about 60 m and have penetrated many geological layers and formations in this region. In this study, we used average velocities of P and S waves in layers, density, and thickness and formation data based on the PS logs in selected 7 boreholes of Yedikule-Sirkeci line. The influences of linearity on the site response analysis have been detected and evaluated with numerical examples. The earthquake data needful for the Equivalent Linear Earthquake Site Response Analyses computer program solution is the Kocaeli earthquake data on 17 August 1999, which was recorded at the earthquake station in Besiktas-Istanbul. In addition to Kocaeli earthquake data, the soil parameters from the boreholes are also transferred and calculated. Thus, important ground features of the area where the engineering structure with huge dimensions are to be constructed have been determined.