Seismic performance evaluation of the Sadabat 1 (V3) viaduct

Abstract

Sadabat V3 was designed in the late 1980's as a connector highway bridge in conjunction of Okrneydam and Hastal on ball-Sakarya motonvay route, which is a major component of the transportation system of Istanbul. The bridge shows some typical examples of old seismic design philosophy such as low level of design forces and lack of modem ductile detailing. Based on the visual inspection, any detrimental effects such as cracking or spalling of cover concrete due to corrosion could not be observed. Generally, it can be say that current condition of the bridge is good. The bridge is evaluated as a critical bridge because of the location on major traveled route. The bridge is expected to remain functional immediately following a destructive earthquake. Seismic performance of the bridge has been assessed by using nonlinear time history analysis and pushover analysis. At the end of the analysis, deformation demand determined fi-om the analysis has been compared with the predetermined component deformation capacity to obtain whether the bridge provides expected performance. Analysis shows that elastomeric; bearings, particularly located on flexible intermediate piers have insufficient displacement capacities in transverse direction to remain elastic. Displacement ductility of the piers are inadequate due to the poor detailing of the plastic hinge region. Because of the low ductility capacity, the piers are unlikely to tolerate cyclic displacement much exceeding yield in transverse direction. However, it can be concluded that the bridge response is essentially elastic in longitudinal direction.