Ongoing research on earthquake behavior of historical minarets in Istanbul

Abstract

Minarets are slender structures. Old ones are mostly made of cut-stone-block masonry and occasionally of brick masonry, while the new ones are generally of reinforced concrete. They have suffered significant damage during past earthquakes, the most recent event being the 23 October 2011 Van, Turkey earthquake. Istanbul is home to many historical and contemporary minarets. Evaluation of their dynamic behavior is significant due to the expectation of a large event in the near future. In a recent study [1] we performed an extensive dynamic characterization campaign in 11 historical minarets in Istanbul, which allowed for the determination of frequencies, modes of vibration and damping. With the help of finite element modeling linear dynamic structural analyses of seven minarets were conducted to assess their earthquake risk level. Herewith we summarize our ongoing studies on the same subject, which are: (1) The minaret damage that took place during the 2011 Van earthquake; (2) The new minaret campaign in Istanbul carried out in 30 historical and modern day minarets; (3) Earthquake damage assessment of the minaret of 16th century Mihrimah Sultan mosque based on discrete element modeling under simulated and real earthquakes; and (4) Permanent strong motion instrumentation of the Hagia Sophia Museum and Maltepe Mosque minarets.