Ground liquefaction caused by 6 February 2023 Kahramanmaraş earthquakes of Türkiye and some assessments on its extent and impacts on built environment

Two disastrous earthquakes, named Pazarcık (M_w7.8) and Ekinözü (M_w7.6), occurred on February 6, 2023 in the southeast part of Türkiye and were collectively named “Kahramanmaraş earthquakes”. These seismic events were caused by a left lateral strike-slip faults, and resulted in significant loss of life, severe damage to infrastructures and buildings, and geotechnical damages such as mainly large-scale slope failures, rockfalls, and ground liquefaction. The main goal of this study is to assess the extend and impact of widespread ground liquefaction, particularly on built environment. Additionally, the ranges of amount of settlement and tilting of buildings due to ground liquefaction were briefly discussed and liquefaction caused by Kahramanmaraş earthquakes were compared with those others occurred in Türkiye. The site observations indicated that except a village, a short section of a highway, a few bridges and two settlements, widespread liquefaction was mainly observed in agricultural non-urbanized fields. The maximum amount of settlement at some liquefaction locations reached up to 2 m and high-raise buildings tilted 7–8° from the vertical reaching up about 20°. Observations indicated that single-storey and two-storeys buildings with a basement to a certain depth, a lower center of gravity and raft foundation should be considered suitable on soils susceptible to liquefaction in earthquake-prone regions without taking any counter-measures against ground liquefaction. Mass movements along the shoreline of the Gölbaşı Lake were unlikely to be caused by lateral spreading resulting from ground liquefaction and they were rather due to planar sliding along a weak layer dipping towards the lake with progressive failure.