Liquefaction Analysis According to Turkish Building Earthquake Regulation (2018) and Sığacık (Seferihisar/İzmir) Case Study

This study includes the investigation of the liquefaction potential of Seferihisar (İzmir) district alluvial soil deposits under possible earthquakes according to Turkey Building Earthquake Regulation (TBER). Seferihisar Yelki fault zone which is one of the branches of the Western Anatolian Fault Line lies under the study area. In order to evaluate this risk, soil survey reports belonging to the buildings licensed by Seferihisar Municipality in Sığacık district which were located by seaside and had possibly high ground water levels, were obtained and investigated, finally 18 drilling data were selected. In this context, initially the liquefaction risk analysis method given in TBER 2018 was briefly introduced and a sample solution was presented in detail. Afterwards, liquefaction risks for different earthquake scenarios were evaluated according to TBER 2018 and presented on the map and possible post-liquefaction settlements were also calculated. In the first scenario, 65% of points were found to have liquefaction susceptibility while that was 47% for the second scenario. In the third scenario, the related area was found to be 71% safe. In addition, possible post-liquefaction settlements were also calculated with two different methods for the first scenario. Finally, the settlements were found to exceed 50 cm for both methods. Calculations were done for each layer throughout the depth and for each layer where is data not available and settlements were found to vary between 8.1 and 27.9 cm.