Page 251 - Çevre Şehir İklim İngilizce - Sayı 4

Ahmet Yakut - Barış Binici

our country, can be described as specific in many respects. First of all, it is such
a rare phenomenon in the world that two earthquakes of magnitude 7.7 and
7.6 struck the same region within 9 hours of each other. These earthquakes are
also quite important considering that it affected a large geography (significant
impact in 11 provinces) and about 13.5 million people living in the region were
directly affected. It should also be emphasized that the measured ground
motion records are much higher than the values given in the earthquake
regulations in some regions (ABYBHY 2007, TBDY 2018, ODTÜ 2023, İTÜ 2023,
BOU 2023). In addition, widespread and severe damage in the areas that are
relatively far from the fault fracture zones and on the soft soil is remarkable in
terms of ground effects (ODTÜ 2023, ITU 2023).
It can be said that the first earthquake with the epicenter of Pazarcık
resulted in a longer fault fracture causing heavy damage in Hatay, Gaziantep,
and Kahramanmaraş. It is understood that the second major earthquake with
epicenter of Elbistan caused heavy damage mainly in Malatya, Adiyaman and
Kahramanmaraş. Examination of the damages in the region reveals that the
majority of the buildings that were destroyed, decided to be demolished
urgently and severely damaged were constructed before 2000. It has been
observed that these structures contain many flaws, especially low concrete
strength, reinforcement detail deficiencies, structural system problems and
application failures, as seen in past earthquakes (ODTÜ 2023). The inadequate
performance of many buildings above mid-rise that have low concrete
strength, structural weaknesses, especially located in the areas on soft soil
with high earthquake impacts, has been revealed again. There are also certain
buildings that were built after the year 2000 but damaged more heavily than
expected due to some deficiencies. According to the statements, about 97
percent of the damaged buildings were built before the year 2000. The causes
of the heavy damage in Kahramanmaraş earthquakes can be listed as follows:
• The ground motion created by the earthquake is greater than the
ground motion based on the building design: It was determined that
the earthquake forces on the basis of the design (response spectra)
which were obtained by the measured records in AFAD stations in
Kahramanmaraş (Göksun, Pazarcık), Fevzipaşa, Gaziantep (Islahiye,
Nurdağı) and Hatay (Antakya, Arsuz, Hassa, Kırıkhan) are greater
than the earthquake forces (design response spectra) specified in
Earthquake Regulations (Figure 7). Thus, certain part of the damage
may have occured for this reason even if the buildings were constructed
in accordance with the earthquake regulations. Actually, it is a desired
approach in earthquake engineering is that the buildings are designed
in compliance with the earthquake regulations and survived the

240 The Journal of Environment, Urban and Climate