Structural Performance Degeneration by Inclusion of a Seismic Joint

This paper presents performance evaluation of a five-story reinforced concrete building that includes dramatic structural performance degeneration. The original building structural system was divided into two blocks with a seismic joint that was included during construction although it was not provided in the design phase. Structural performance evaluation is performed according to Turkish Earthquake Resistant Code 2007 (TEC-2007), which is very similar to modern codes. Nonlinear static pushover analysis was performed in order to draw the capacity curves of the building in two orthogonal directions. Equivalent incremental seismic load method that is defined in TEC-2007 is followed for earthquake performance evaluation. The building does not satisfy the target structural performance levels shown in TEC-2007. It is concluded that the fundamental reason for the poor performance is the inclusion of the seismic joint. The seismic joint transforms the building into two blocks irregular in plan, which results in the degeneration of the buildings structural performance.