A preliminary microzonation study on Northern Coasts of Izmir: Investigation of the local soil conditions

In this paper, distribution of the dynamic soil properties in a region comprising the majority of the Izmir Karşiyaka municipality borders is investigated. A number of geotechnical and geological parameters of the region, which involve the results of formerly and recently drilled borings as well as the results of the geotechnical tests performed on undisturbed specimens are considered. Moreover, collected data, and the variation of dynamic soil properties in the region is demonstrated utilizing a Geographical Information System (GIS) software, in which a square grid of 250. m cell size is determined. The variation of the average shear wave velocities in the upper 30. m of the region as well as the soil classes among NEHRP are thematically investigated to determine the variation of soil properties in the region, which may be triggered by high water table at alluvial areas. Simulated ground motions are created using a scenario earthquake on active Izmir fault of 6.9 magnitude, having an average distance of 10. km to the region under investigation. As a consequence, these motions are utilized to map the distribution of maximum spectral amplifications, maximum surface spectral accelerations as well as the ground shaking maps, for a better understanding of the risk in the region. © 2012 Elsevier Ltd.Dokuz Eylül Üniversitesi City, University of London, CityThe contributions of Ege University Research Funds, T U ¨ BİTAK and EBİLTEM with projects 2004-MUH-028 , 105-M-336 and 2007-BIL-023 are highly appreciated. The authors are also thankful to Ege Temel Sondajcılık, ZETAS and ZEMSON for sharing the field exploration results with us. Geological overview of Izmir city is supported by contributions of Yalçın Koca and Cem Kıncal from Dokuz Eylül University, which deserve authors’ gratitude. The authors would like to thank Prof. Ellen Rathje from University of Texas at Austin for her help in constitution of stochastically simulated ground motions. Lastly, the authors would like to thank chief editor Mustafa Erdik and an anonymous referee for their valuable comments and contributions. -