Evaluation of the Effect of Change in Support Conditions on the Seismic Behavior of a Historical Masonry Bridge

Abstract

It is believed that the Yılanlı (or Leylekli) Bridge (bridge with stork or snake figures) in Tokat, a city with high seismicity, was built during the Roman or Byzantine period. Although no structural damage was found on the bridge, which is still open to pedestrian traffic, it is very important to determine the seismic behaviour of the bridge considering the possible earthquakes to which the structure will be exposed. This article presents the seismic response of the historical Yılanlı (Leylekli) Bridge, which has been subjected to unfavourable human-made changes in geometric shape over time. The original and modified shapes of the bridge were modelled using the macro modelling approach in ANSYS finite element software. The structural performance of the models was evaluated in terms of stresses, deformations, and especially cracks on the arch and spandrel walls using nonlinear static and time history analyses. The results of the analysis show that the change in shape, which is not desirable from an architectural and aesthetic point of view, adversely affects the seismic performance of the historical bridge and makes it more vulnerable to possible earthquakes. In addition, the analyses clearly showed that both models are subject to serious structural damage that could lead to a collapse in the event of a potential large magnitude earthquake.