Case Study
Predicting Earthquake Damage to Masonry Structures
 LUSAS has been used to
investigate the safety of the Hagia Sophia mosque in Istanbul, Turkey, during an
earthquake and to determine if any strengthening or repair work is required.
Hagia Sophia (Aya Sofya) was once an early Greek church, built during
the Byzantine period and for one period of 800 years it was the largest structure in the
world. During this time it was affected by many earthquakes resulting in several
reconstructions of different parts of the main dome and repair of some structural
elements. The effects of previous seismic activity can be seen all over the building.
In a project financed by the Turkish Ministry of
Culture and the US National Science Foundation, Professor Ahmet Cakmak of Princeton
University, USA and Professor Mustafa Erdik of Bogazici University, Turkey investigated
the dynamic properties of the structure and its behaviour during an earthquake which may
be caused by a fault passing 25km to the south of Istanbul. In order to accomplish this
task the team used a number of advanced measurement and analysis tools including:
- Laser interferometry techniques to check key dimensions of the building
- Accelerometers to measure the structural response during tremors and
earthquakes
- LUSAS finite element analysis to predict natural frequencies and likely
areas of damage in the structure.
The team decided to use LUSAS because it has excellent
facilities for predicting the nonlinear transient response of structures and a wide range
of high performance elements. Nonlinear material models in LUSAS are used to predict local
damage and failure mechanisms in the structure. Results obtained using LUSAS indicate that
damage will occur initially in the west and east semi-domes before proceeding to the
arches and main dome.
Other analyses performed using LUSAS finite element analysis
include the Hagia Eirene church and Suleymaniye mosque in Istanbul.
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