Two earthquakes, Mw = 7.8 Kahramanmaras,-Pazarcik, and Mw = 7.6 Elbistan, occurred on February 6, 2023, approximately 9 h apart. These earthquakes caused devastating effects in a total of 11 nearby cities on the east side of T & uuml;rkiye (Adana, Adiyaman, Diyarbakir, Elazig, Gaziantep, Hatay, Kahramanmaras,, Kilis, Malatya, Osmaniye, and S,anliurfa) and the north side of Syria. These earthquakes provided an outstanding prospect to observe the effects of liquefaction in silty sand and liquefaction-like behavior in clays (cyclic softening) on the stability of structures. This paper specifically presents the post-earthquake reconnaissance at three sites and evaluations of four buildings within these sites in Adiyaman Province, Golbas, i District. First, important role of post-earthquake piezocone penetration test (CPTu) in characterizing the subsurface conditions was presented. Then, the effect of soil liquefaction and cyclic softening on the performance of four buildings during the earthquakes was evaluated. These structures represent the typical new reinforced concrete buildings in T & uuml;rkiye with 3 to 6-story, situated on shallow (raft) foundations, and demonstrated diverse structural performances from full resilience to moderate and extensive damage during the aforementioned earthquakes. Based on the interim findings from these sites, the potential factors that caused moderate to severe damage to buildings were inspected, and preliminary-immediate insights were presented on the relationship between structural design, soil properties, and the performance of buildings with shallow foundations.

On 6 February 2023, two independent earthquake pairs on the East Anatolian Fault Zone, with epicenters in Pazarcik (Mw = 7.7) and Elbistan (Mw = 7.6) districts of Kahramanmaras province, caused great destruction. Adiyaman and Golbasi districts of this city are among the settlements most affected by the earthquake. Especially in the district where geotechnical damages are most observed, the destructive effects of earthquakes have been clearly observed in buildings with different structural systems. In this study, information is given about the earthquakes that hit the region and the fault zone where the earthquakes occur. Geotechnical and structural damages occurring in the villages and center of the district were evaluated within the scope of earthquakes and structural engineering. It can be stated that damages observed in the district center are generally caused by soil-structure interaction problems. The fact that masonry structures, which are widely used in rural areas, do not benefit from any engineering services has an impact on the level of damage. The main reason for the damages occurring in the reinforced concrete structures in the district is the reinforced concrete system that is not designed properly or not built in accordance with the design. This case study demonstrated the importance of earthquake-soil-structure interactions in line with earthquake-resistant building design principles.

On February 6th 2023 two major earthquakes struck southeast Turkey, M7.7 Kahramanmaras and M7.6 Elbistan, respectively. Unfortunately, due to the impact of these catastrophic events more than 50 000 casualties and 35 000 collapsed buildings have been reported since then. The aim of the study is to demonstrate preliminary site response analysis and assessment of re -liquefaction potential of sites which have been affected by the earthquakes - especially the cities of Iskenderun and Golbasi. Both site -specific areas have clear evidences of liquefaction and lateral spreading events which imply the focus of the presented paper. A series of geophysical MASW and microtremor tests have been performed in order to determine shear wave velocities up to depth of 30 m as well as the fundamental natural frequency of the soil deposits. Moreover, samples have been collected from sand and silt ejecta in order to evaluate some basic physical properties - grain -size curves, specific gravity and plasticity parameters. On the basis of the obtained data seismic classification of the investigated sites according to current design codes has been made and in-depth distance to relatively stiff layer has been assumed. For the sake of evaluating risk of re -liquefaction the widely -used simplified stress -based approach to triggering assessment has been adopted considering some rules of the thumb (e.g., sieve analysis and plasticity properties evaluation). Lastly, post -liquefaction reconsolidation settlement and lateral displacement have been determined in terms of future earthquakes.