Geoteknik veri işleme ve haritalandirmada CBS kullanimi: Antakya örneği

Geographic Information Systems (GIS) is a data collection tool that offers various features, including the analysis, querying, visualization, statistical analysis, and spatial analysis of geographical data. In the context of construction areas and urban planning, GIS is used for digital mapping studies, allowing for a more effective examination, interpretation, conclusion, and planning of data. The aim of this study was to mitigate risks associated with geotechnical issues, specifically seismic site effects and weak soil properties. To conduct the study, geotechnical survey reports and field and laboratory test results from the archives of the Provincial Directorate of Environment and Urbanisation of Antakya were utilized. In an area of approximately 110 km² within the Central District of Antakya Province, geological, geophysical, and geotechnical data from 221 borehole logs were analyzed using the GIS Inverse Distance Weighting (IDW) method. Engineering properties of the soils were examined at various depths (1.5, 3.0, 6.0, 7.5, and 9.0) within the study area. The analyses conducted included the standard penetration test, bearing capacity, groundwater level, consistency limits (LL, PL and PI), shear wave velocity, and soil classification based on NEHRP, EUROCODE-8, and TDBY2018 earthquake regulations. The standard penetration test (SPT-N) indicated blow numbers ranging from 2 to 50. A total of 1680 soil samples were classified into five different groups (CH, CL, MH, SC, and SM), with clayey soil samples dominating 91% of the study area. Shear wave velocity analysis at a depth of 30 meters categorized the soil classes as B and C according to the EUROCODE-8 classification, or C and D according to NEHRP and TDBY2018, indicating their importance in evaluating the seismic characteristics of the soil. The bearing capacity ranged from 0.2 to 6.6 kg/cm2 for the first 1.5-meter depth, increasing as depth increased and ranging from 0.4 to 11 kg/cm2. The study area also included flood-prone areas surrounding Amik Lake and river flood-prone areas, with groundwater levels fluctuating between 1 and 10 meters. The predominant geological composition in the Antakya region consists of Quaternary alluvial fill, comprising clay, silt, and sand. These alluvial materials tend to amplify ground motions during earthquakes, emphasizing the importance of identifying and mapping such areas for further studies. Keywords: Antakya, GIS, geotechnics, geophysics, mapping.