Seismic evaluation and retrofit of damaged R/C buildings

A severe earthquake measuring Ms 6.2 occurred near the city of Ceyhan (population 100 000) in Southern Turkey on 27 June 1998. Although the focal distance to Ceyhan was 32 km, fault rupture was directed towards Ceyhan, causing heavy damage in the city as a result of a strong motion with a PGA of 0.28 g. Out of a total number of 146 casualties, 86 were in Ceyhan. Twelve R/C buildings collapsed and 120 were classified as moderately damaged in Ceyhan. These 120 multistory buildings have been inspected and their seismic retrofit projects have been prepared by the Earthquake Engineering Research Center of the Middle East Technical University (METU/EERC). The retrofit works include detailed damage assessment and structural evaluation of the existing buildings, selection of the retrofit scheme, and final performance verification by the capacity spectrum method. Cast in place concrete infill walls are employed as the primary elements of seismic retrofit. The selected retrofit scheme has provided the required seismic safety and economy.