The Effects of Construction Techniques and Geometrical Properties on the Dynamic Behavior of Historic Timber Minarets in Sakarya, Turkey

Sakarya City, as the host of many civilizations, has many historic monuments. The city is in the most active earthquake zone in the region. The minarets of mosques are the most important structures because they are slender. Therefore, they are sensitive to lateral loads, and earthquakes and strong winds may cause damage to these structures. The highest number of mosque minarets partly or totally collapsed in the 1999 Kocaeli and Duzce earthquakes that occurred in Turkey. The region is rich in trees, so timber has been used in the construction of different structures in Sakarya City and the vicinity for many years. In this study, five historic timber minarets in Sakarya City were experimentally and computationally examined to determine the effects of the construction techniques and geometrical properties on the dynamic behavior of the minarets. Ambient vibration tests of timber minarets were performed, and the construction techniques and geometrical features were examined; the results of these arc discussed below. It was determined that the outer wall construction technique, body height, slenderness, and cross-sectional area play important roles in the dynamic behavior of timber minarets. Finally, an empirical formula was derived from the relationships for rapid estimation of the fundamental period of timber minarets.