Geotechnical assessment of Gazi oPsman Paşa District in Yalova province

Yalova is a province with an increasing population and is open to growth, as it is adjacent to Turkey's largest cities in terms of population density in the Marmara Region. Although Yalova is a province open to growth due to its location, the entire province of Yalova is in the 1st degree earthquake zone. The reason why it is in the 1st degree earthquake zone is that it is located on the seismically active NAF Line (North Anatolian Fault Line). Since the earthquake poses a great risk for Yalova province, processes such as ground survey, project design and manufacturing phase of the building to be built need to be examined and researched in more detail and a decision must be made. Earthquakes and liquefaction on the ground where buildings sit cause great damage to the structure. The importance of liquefaction analyzes increases in areas such as Yalova, where the underground water table is close to the surface. While making a geotechnical evaluation of the region that is the subject of our thesis, the liquefaction potential and bearing capacity analyzes of the ground were examined. Liquefaction potential analyzes were calculated in accordance with the rules specified in Idriss and Boulanger and the Turkish Building Earthquake Regulation. For carrying capacity calculations; TBDY 2018 methods, which use the same correlations as Terzaghi, Meyerhof, Vesic and Vesic in the literature, were used. In our study, ground survey studies of 41 parcels were used. A total of 223 boreholes were examined in these 41 parcels, depending on the size and type of the structure to be built on them, and the most critical borehole data for each parcel were examined in our study, taking into account the SPT values. The groundwater level in the region varies between 3.00 and 7.50 depending on the season and weather conditions, but according to the drillings examined, it was seen that there was no groundwater level in some parcels. According to the results of the analyses, it was observed that the liquefaction potential of the ground increased on the eastern side of our study area, which is close to the sea, and on the northern side of the region facing the Yalova-Bursa road. It has been determined that ground improvement methods should be used before construction, especially in these areas.