EFFECT OF PULSE-LIKE GROUND MOTION ON STRUCTURAL DAMAGE IN HATAY PROVINCE AFTER THE KAHRAMANMARAŞ EARTHQUAKES

Following the 7.7 and 7.6 Mw earthquakes in Kahramanmaraş, thousands of buildings collapsed and sustained severe damage in eleven provinces across Türkiye. Additionally, there were 42922 aftershocks in the aftermath of the earthquakes. The province of Hatay, located approximately 100-150 km away from the epicenter, was the most severely affected. Data obtained from accelerometer stations revealed significant effects of supershear, directivity, and high vertical ground motion. The discussions that followed the earthquakes presented both supporting and opposing viewpoints on the presence of supershear effects. The extensive damage observed along the fault line after the earthquakes served to highlight the significance of near-fault effects, further corroborated by the recorded data. The records obtained along the fault line exhibited notable pulse effects indicating directional influences in displacement-time and velocity-time histories. Another distinctive feature of the earthquake was the occurrence of high vertical ground motion. In some regions, vertical ground motions exceeded the horizontal ground motions, with values ranging from 0.6 to 1.0 g, as observed in accelerometer station data. This study presents the findings of a comprehensive field investigation in Hatay that took all of these effects into account. The field research team conducted a detailed study to assess the extent of damage in the region and understand the factors contributing to it. Understanding the characteristics of earthquakes, recognizing fault lines, and evaluating the response of structures are of paramount importance for preparing for expected future earthquakes.