Investigation of local site conditions in the Oba Plain (Alanya-Antalya) via microtremor method

This thesis study covers microtremor measurements, determination of dynamic properties of soils in Cumhuriyet Quarter and Obagöl Quarter of Oba Plain (Alanya- Antalya), preperation of site response spectra, investigation of predominant periods and amplification magnification coefficients. The study area includes so-called geotechnically weak soils such as soft clay and peat. The groundwater level in the region is close to the surface. The earthquakes experienced in Alanya, the fact that the study area consists of problematic soils and the shallow ground water were effective in the selection of the study area. Microtremor measurements were performed at 18 points to determine the soil predominant periods and amplification coefficients. Microtremor recordings were evaluated with Geopsy software. Peak ground acceleration of the region was identified according to the current Turkey Earthquake Hazard Map, and appropriate records were selected from Turkey the earthquake database. For 8 different locations in the study area, the response spectrum curves were generated using shear wave velocity profiles obtained from MASW measurements. The data obtained were subjected to equivalent linear analysis in EERA software, which visualize the dynamic behavior of the soil, and the dynamic behavior of the soils in the region was investigated. Graphs of acceleration spectra on bedrock and ground surface were generated. By comparing the graphs created, the extent of the amplification of the input bedrock movement to the ground surface movement. According to the results of the equivalent linear analysis performed in the EERA software, it was observed that the soils had greater amplification at 0.5 seconds on average, and the predominant periods occurred in an average of 0.8 seconds according to the microtremor results.