Abstract

Two destructive earthquakes (Mw: 7.7 and Mw: 7.6) occurred in Kahramanmaraş, Türkiye, on February 6, 2023. The epicenters of these two earthquakes were very close to each other (approximately 90 km apart), and both took place on the same day. The first earthquake occured at 04:17 local time with a magnitude of 7.7 and a depth of 8.6 km, while the second earthquake occurred at 13:24 local time with a magnitude of 7.6 and a depth of 7.0 km. These two earthquakes caused extensive damage, particularly in 11 provinces, with Adıyaman being one of the hardest-hit areas. Most buildings in Adıyaman were severely affected or collapsed as a result of the earthquakes. Reports indicate that over 35,000 buildings collapsed in the aftermath. Furthermore, between February 6, 2023, and May 6, 2023, more than 30,000 aftershocks, ranging in magnitude from 0.2 to 6.6, were recorded. In this study, earthquake damages in reinforced concrete buildings in Adıyaman province were evaluated. The causes of damages in reinforced concrete buildings were evaluated in terms of material quality, design of building and reinforcement details. Field observations are also provided, along with accompanying pictures. The earthquake regulations in Türkiye, established in 1975, 1998, 2007, and 2018, which apply to a significant portion of the country’s buildings, are discussed. An evaluation was conducted to assess whether the damaged buildings complied with the earthquake regulations in Türkiye. Field observations revealed that the earthquake regulations, particularly in relation to reinforcement details, were overlooked. In addition, designers should avoid design mistakes such as to make discontinuous of frames, to place most of vertical element strong axis in one direction, insufficient support condition of stairs and adjacent building effects.

Introduction

Türkiye has active earthquake fault zones, including the North Anatolian Fault, East Anatolian Fault, and West Anatolian Fault zones, which have the potential to cause destructive earthquakes. Türkiye has often been exposed to destructive earthquakes in the past. After these earthquakes, many studies about structural failures have been conducted and documented in the literature [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]. On 6 February 2023, two destructive earthquakes occurred in Kahramanmaraş provinces in Türkiye (Mw: 7.7 and Mw: 7.6). The first earthquake was occurred in Pazarcık (distinct of Kahramanmaraş) at 04:17 local time with a magnitude of Mw:7.7. The second earthquake was occurred in Elbistan (distinct of Kahramanmaraş) at 13:24 local time with a magnitude of Mw:7.6. These two earthquakes were occurred in same day (approximately nine hour apart) and there is approximately 90 km distance between epicenters of these earthquakes [13]. The pair of earthquakes resulted in significant structural damage, particularly impacting 11 provinces, including Kahramanmaraş, Hatay, Gaziantep, Malatya, Diyarbakır, Kilis, Şanlıurfa, Adıyaman, Osmaniye, Adana, and Elazığ, where many buildings either sustained severe damage or collapsed entirely.

According to official announcements from the Disaster and Emergency Management Authority (DEMA) on 2 June 2023, it was reported that over 35,000 buildings had collapsed after the earthquakes. Furthermore, during the period from February 6, 2023, to May 6, 2023, more than 30,000 earthquakes with magnitudes ranging from 0.2 to 6.6 were documented [13]. The Kahramanmaraş earthquakes had a profound impact on Türkiye, causing severe damage not only during the initial earthquakes but also due to subsequent aftershocks.

Conclusions

Two destructive earthquakes occurred in Pazarcık (Mw: 7.7) and Elbistan (Mw: 7.6), Kahramanmaras¸, Türkiye. These earthquakes severely affected 11 provinces (Kahramanmaras¸, Hatay, Gaziantep, Malatya, Diyarbakır, Kilis, S¸ anlıurfa, Adıyaman, Osmaniye, Adana,Elazıg). Adıyaman is one of the provinces most affected by the earthquakes. Due to these two earthquakes occurring on the same day ˘ (nearly 9 h apart), damaged buildings were only examined after the second earthquake. This study focuses on examining the damaged reinforced concrete buildings in Adıyaman. Structural damages and the reasons for these damages are examined in comparison with Türkiye Earthquake Codes.