ABSTRACT
Historical masonry structures are vulnerable to seismic loadings due to their architectural characteristics, unsuitable strengthening or retrofit techniques, according to post-earthquake scenarios observed in Turkey during the previous 50 years. Masonry arch bridges are among the most important architectural heritage buildings vulnerable to earthquake motion. Historic masonry bridges that have suffered severe damage highlight the need for preventive and focused risk reduction strategies. This study aims to analyze the seismic vulnerability of two historical masonry arch bridges located in the Northeast and Northwest of Turkey, considering the seismotectonic parameters of the region. Nonlinear behavior of the masonry arch bridges under the seismic excitations that can be expected at the site was simulated in order to predict the potential damage levels. Discrete element method based on the numerical integration in time of the equations of motion of the system by means of an explicit finite difference method was used. The explicit solution procedure uses small time steps for numerical stability and this methodology allowed a general analysis to assess the joint separation and sliding of stone blocks. The seismic responses of these two masonry bridges showed that the geometry of the bridge has a significant effect on the structural performance, especially the arch span, which increases the seismic vulnerability of the bridges. More research is still needed on the approaches available to improve the seismic safety of damaged masonry arch bridges while preserving their historical value.
