Gaziantep Kurtuluş camisinin deprem davranışının incelenmesi

Yıl 2016, Cilt: 7 Sayı: 3, 455 - 470, 01.12.2016

Hamza Güllü Murat Karabekmez

Öz

Kültürel mirasımızın önemli parçasını oluşturan tarihi yapılar, potansiyel bir deprem tehlikesine sahip olan
ülkemizde sürekli deprem etkisine maruz kalmakta ve depremler sebebiyle hasarlara uğramaktadırlar. Bu
yüzden, tarihi yapıların deprem altındaki davranışlarının incelenerek, geleceğe güvenli bir şekilde
aktarılması oldukça önem arz etmektedir. Bu çalışmada, 125 yıllık tarihi yığma bir yapı olan Gaziantep
Kurtuluş camisinin depreme karşı davranışı incelenmiş ve muhtemel hasar potansiyeli değerlendirilmiştir.
Bu kapsamda, katı elemanlar kullanılarak sonlu elemanlar yöntemi ile yapının üç boyutlu sayısal modeli
oluşturulmuştur. Deprem etkisi, zaman-tanım (time-history) alanında tanıtılan özel olarak seçilmiş 10 adet
senaryo deprem kayıtları kullanılarak incelenmiştir. Yapıdaki davranışlar deprem hareketinin nonlineer
etkisine göre hesaplanmıştır. Dinamik etkiler, alternatif olarak önerilen hızlı nonlineer analiz (FNA) yöntemi
ile belirlenmiştir. Deprem hareketi X ve Y olmak üzere iki ayrı yönde uygulanmıştır. Analizler sonucunda
deprem etkisi altında camide oluşan yer değiştirme, ivme, gerilme (çekme ve basınç), taban kesme kuvveti,
doğal titreşim periyodu ve titreşim modları hesaplanmıştır. Analiz bulguları, camide bazı bölgelerde yer
değiştirme ve çekme gerilmelerinin müsaade edilebilir sınır değerleri aştığını göstermiş olup hasar riski
oluşturmuştur. Ayrıca, caminin hesaplanan doğal titreşim periyodunun (0.5s), depremin hakim periyoduna
(0.35s) yakın seyrettiği belirlenmiştir. Bu durum deprem etkisi altında camide rezonans meydana
gelebileceğine işaret etmiştir. Elde edilen bulguların camide yapılacak restorasyon çalışmalarına katkı
sağlayacağı düşünülmektedir.

Anahtar Kelimeler

Tarihi yığma yapılı cami, deprem, sonlu elemanlar, doğal titreşim periyodu, hasar

Investigation of earthquake response of Gaziantep Kurtuluş mosque

Öz

The seismic assessment of historical structures is a
fundamental issue nowadays for protecting the
cultural heritage. In many countries, masonry
structures still play a central role for representation
of country’s history and its development. Most of
these structures have a historical and architectural
value in both, thus they are permanently needed to
ensure their reliable seismic safety with accurate
analysis tools. Accordingly, nowadays, the most
advanced computer based methods employing
numerical package softwares available for
structural assessment have been used to analyze the
behavior of historical masonry structures, resulting
in different levels of complexity and cost in the
viewpoint of computational effort. Damage risk of
the most vulnerable masonry historical structures
should be minimized to avoid significant social and
economical losses. These requirements are
particularly evident in historical masonry mosques,
since their assessment is strongly needed for
restoration by administrative authorities frequently.
Several procedures have been employed in last
decades in order to predict the behavior of masonry
structures. The difficulty in representing the
behavior of the material and the structural
resistance requires the use of effective structural
model. Nonlinear analysis is the most
comprehensive procedures to study the complex
behavior of masonry structures during an
earthquake, since more reliable solution can be
obtained as compared to conventional linear
approaches such as collapse mechanisms, ductility,
forces redistribution, damage, etc. In principle,
nonlinear time-history analysis is the most suitable
seismic assessment tool, but it needs fast algorithms
to obtain the solutions more practice. Moreover,
dynamic nonlinear analysis is strongly dependent on
the input excitation and has a high computational
time and effort, which must be seriously considered
when complex structures are analyzed.
Historical buildings that become an important part
of our cultural heritage in Anatolia are mostly
subjected to earthquake effects in our country.
Therefore, they have a dangerous earthquake
potential, which results in significant damage. Thus,
it is quite important to transfer the historical
structures to next generations through the
investigation of their responses under earthquake.
In this study, the behavior of a 125-years old
historical masonry structure, Gaziantep Kurtulus
mosque, was studied against earthquake effect, with
an evaluation of possible damage potential. For this
purpose, three-dimensional numerical model of
Kurtuluş mosque was built with finite element
method. Solid elements were used for the building of
the numerical model due to finite element. The
dynamic effects due to earthquake motions for the
dynamic responses of structure are estimated in a
time-history domain employing some possible
records of scenario earthquakes. The scenario
earthquakes included 10 strong ground motions that
were selected to represent the earthquake effect to
Gaziantep city in the viewpoint of peak ground
acceleration as a preliminary assessment in this
study. The earthquake motions have been exerted to
the numerical model of structure under
consideration of nonlinear stress-strain behavior of
dynamic excitation. Fast nonlinear analysis (FNA)
method was used for the nonlinear behavior of
earthquake motion. The FNA methodology has also
been applied to provide less time and computational
effort in the study. Under the earthquake excitation,
the structural behavior has been calculated and
evaluated in the responses of displacement, stress,
acceleration, predominant period and mode of
vibration. The computations have been carried out
using SAP2000 package software.
As a consequence of the analysis, the findings
obtained show that displacements and tensile
strengths in some part of the mosque exceed their
allowable limits. This indicates that the mosque has
a potential damage hazard under a possible
earthquake. In addition, natural vibration period of
mosque (T=0.5s) is found to close to predominat
period of earthquake (T=0.35s). This could result in
the mosque and earthquake vibration to be in
resonance that could also cause a potential damage.
The study with the findings could be considered to
be beneficial for the local authorities during the
restoration of Kurtuluş mosque.

Anahtar Kelimeler

Historical masonry structure, earthquake, finite element, natural vibration period, damage