Seismic hazard anlysis of Bilecik region and determination of soil liquefaction potential and forming a liquefaction risk map

Under the influence of strong ground motions caused by earthquakes, water-saturated loose cohesionless soils may liquefy. Soil liquefaction occurs as a result of earthquake vibrations and the increase in water pressure in soil voids, resulting in zero effective soil stress and loss of shear strength. When the soils liquefy, it causes major settlements in the foundations of the structures on them and the collapse and damage of the structures. In addition, sand boiling, lateral spreading, deformations and slope movements (slides) occur in liquefied lands. Therefore, it is important to determine the soil liquefaction risk for buildings and settlements. Within the scope of this study, first of all, all the important seismic sources and their geometric and geological characteristics in the area with 150 km radius of Bilecik, Gölpazarı, Osmaneli, Söğüt, Bozüyük and Pazaryeri settlements were determined and then the magnitudes of each of them and the maximum peak bedrock accelerations were calculated using the deterministic method. Then, in accordance with TBDY 2018, liquefaction risk analysis methods based on Standard Penetration and Shear Wave velocity field tests were programmed in Excel and liquefaction risk analyzes of these six regions are made based on a certain number of geotechnical reports.