Interpretation of geotechnical risk maps for Malatya province in terms of earthquake sequence on February 6, 2023

Abstract

The earthquake sequence that occurred on February 6, 2023, centered in Türkiye caused extensive loss of life and significant damage. In this study, the geotechnical properties of the central districts of Malatya province, one of the provinces affected by these earthquakes, were calculated using data obtained. In the calculations, the correlations suggested by the Turkish Building Earthquake Code (TBEC) and internationally recommended correlations were used. Thus, the difference between the methods proposed by TBEC and internationally recommended correlations was interpreted. Using 1890 drilling data, 1765 seismic data, and 1764 microtremor data, calculations were made to determine bearing capacity values for 3 m x 3 m pad foundation, liquefaction potentials of the soil and soil classifications around this region. The results obtained from the calculations were mapped with geographical information systems-based software. Results of the study revealed that 2.9% of the study area in Battalgazi district and 1.71% for Yeşilyurt district had liquefaction potential. Almost 80% of each district was found to have a soil class of ZD (medium dense gravel and sand or clay layers) according to TBEC. The findings of the study were compared with previous studies, satellite images of the study area and post-earthquake observations. In areas where damage caused by the earthquake sequence was observed intensively, bearing capacity values were relatively low. It was concluded that building on poor soil conditions poses a profoundly serious risk in terms of earthquakes and very serious precautions should be taken by gathering several disciplines during the construction of these structures.