Page 243 - Çevre Şehir İklim İngilizce - Sayı 4

Ahmet Yakut - Barış Binici

Introduction

Buildings that were constructed before 2000 (around 90 percent of the total
building stock) in our country constitute about 48 percent of the building stock
with the exact data on their construction year. The average floor height of our
buildings is around 5, which is 7.1 (the highest) in Ankara and 6.9 in İstanbul
(TUİK, 2021). As has been revealed in the past earthquakes, the earthquake
performance of low- and mid-rise reinforced concrete buildings, which
constitute the majority of our building stock in urban areas, is not sufficient. It
would be appropriate to divide the building stock in our country into two as
pre-2000 and post-2000 structures in terms of earthquake risk. It can be said
that the changes in building design, material and construction that are made
around 2000 significantly affect the earthquake risks of buildings constructed
after this date. The earthquake regulation (ABYBHY 1998), which entered into
force in 1998, contains modern and up-to-date calculations and provisions on
earthquake-resilient building design. According to the 1975 regulation, which
was valid until that date, comprehensive provisions were introduced both on
the determination of earthquake effects and on the design and detailing of
structural elements (Yakut et al. 2021, İlki, and Celep 2012, ODTÜ 2020). The
Kocaeli and Düzce earthquakes, which occurred about 1 year after the entry
into force of the 1998 regulation, caused a significant increase in awareness
about the earthquake reality in our country and the risk of our structures,
and led to the initiation of many studies on earthquake risk nationwide.
Following the revision of Requirements for Design and Construction of
Reinforced Concrete Structures (TS500, 2000) in 2000, the use of ready-mixed
concrete and steel of certain quality became mandatory in buildings. With
the enforcement of Law No. 4708 on Building Inspection in 2001, it was aimed
to provide inspection on projects and buildings in order to construct high
quality structures in accordance with the standards and regulations. Building
inspection was implemented primarily in 19 pilot cities, then expanded to
whole country and became mandatory in 2011.
This article aims to evaluate the risk levels of our buildings by examining
the seismic performances of RC buildings, which constitute the majority
of our building stock, observed in the past earthquakes by focusing on
Kahramanmaraş earthquakes occured on February 6, 2023, in particular. Then,
recommendations are provided for the reduction of these risks through a road
map by identifying the factors leading to structural risk.

232 The Journal of Environment, Urban and Climate