A DETAILED DAMAGE SURVEY ON REINFORCED CONCRETE BUILDINGS IN 2023 TURKEY EARTHQUAKE

Following the strong consecutive earthquakes in Turkey on February 6th, 2023, a damage reconnaissance team coordinated with the Architectural Institute of Japan consisting of several groups, together with an expert Turkish team, was dispatched to the earthquake-hit area. In total, 25 reinforced concrete (RC) buildings in Malatya, Adiyaman, Kahramanmaras, Gaziantep, and Hatay provinces were inspected in a five-day mission. The main interest of this article is to report the details of the damage investigation of six of the surveyed buildings. The selected buildings were constructed after the year 2000, which is a critical date for the Turkish construction industry because of the revision of building codes and, thereby, significant changes in the quality of construction. The revisions to the Turkish Building Earthquake Code (TBEC) of 1998 took effect on site practically around the year 2000. The guideline “Requirements for Design and Construction of RC Structures,” which introduced such modifications as detailing of shear reinforcement, prohibition of the use of low-strength concrete, and plain bars, was introduced the same year. This paper reports the major damage to each building's structural elements and non-structural elements, such as infill walls in the first place. Based on the damage status of each element, the damage level is assigned to each, following the guidelines for earthquake damage classification in Japan. By considering the residual strength of each element based on the values recommended in the guideline mentioned above, the residual horizontal load-bearing capacity of the building is roughly evaluated. This strength reduction value would define the degree of damage to the building. The damage to the surveyed buildings in this survey varies from minor to severe. The generated result could essentially assist the building owners and city authorities in deciding whether to repair/retrofit or demolish the building if conducting a secondary inspection or detailed computational analysis is not required. Furthermore, the effective cross-sections of the walls and columns were calculated based on the data collected via the in-place measurements. By adopting a simplified seismic performance equation in the “RC Design Code” of Japan, the sufficiency of the lateral load-bearing capacity of each building was roughly estimated.