Abstract- Kaya MSc.
SEISMIC PERFORMANCE EVALUATION OF THE VIADUCT (V1)
(Thesis Supervisor: M. Nuray Aydınoğlu)
Viaduct V1 was designed in 1995 and is located on the motorway, which is still being constructed between Kavacik and Beykoz. Although the Viaduct V1 is not located on an important route in Istanbul, and has no much importance in the transportation system of Istanbul yet, the importance of Viaduct V1 will rise in the near future with the growing migration to city. Based on visual inspection of the Viaduct V1, no cracking or spalling of cover concrete due to corrosion has been observed. Furthermore it can be easily said that the current condition of the bridge is pretty good. The bridge was evaluated as an important bridge, which is expected to remain functional after a destructive earthquake. The performance of the bridge has been assessed using response spectrum analysis and time history analysis tools. In order to understand whether the bridge needs any retrofit and whether the bridge provides the expected performance, deformation demands of the elements and the forces acting on them have been compared with the predetermined element capacities. Analysis show that the elastomeric bearings located on Pier3, Pier4, Pier7, PierlO and Pier12 are highly susceptible to failure in longitudinal direction. Another problem found from the results is the pier top deformation demands in the transverse direction. These deformation demands exceed the gap distance between two bridges, so there is a high probability that two bridges would pound against each other in the transverse direction. In spite of the pounding probability of two bridges, it can be said that the response of the piers is elastic in both longitudinal and the transverse directions. Only one retrofit measure has been proposed for the Viaduct V1 in order to capture the expected performance. Steel connectors have been placed in the transverse direction between two bridges in order to prevent the pounding effect. Also laminated elastomeric bearings located on Pier4, Pier7 and PierlO have been replaced with lead-rubber bearings. Satisfactory results have been obtained with the mentioned retrofit measures.