Evaluation of Successful Seismic Bridge Design Practice in Turkey

On October 23, 2011, a destructive earthquake of $M_{\mathrm{w}}=7.1$ occurred in Eastern Turkey. The event occurred on a previously unknown fault with a thrust mechanism and resulted in 604 deaths and major structural damage to the buildings. The highways at the Van earthquake zone were open to service of rescue operations, aid trucks, and regular traffic immediately after the devastating event. As a success story, the bridges closer to the fault line than the towns of Van and Erciş were observed to have minimal damage, such as minor support movements and cracks at the shear keys. Among the 14 highway bridges in the region evaluated by the authors, only two adjacent bridges, Bendimahi-II, had minor structural cracking along the column height. As expected, the bridges of concern were observed to perform in the essentially elastic state. The main focus of this study was to evaluate the seismic bridge design practice in Turkey, which resulted in a successful seismic performance of the earthquake-zone bridges. As an illustrative example, Bendimahi-II bridge, the closest one to the fault line, was studied through an analytical investigation.