Seismic performance of existing R.C. framed buildings

The earthquakes disasters basically occur due to buildings damage not because of the earth shaking. Therefore, the countries have being updated the seismic codes. The seismic loads for buildings design in Egyptian Code have been changed from (EC-1994) to (ECP-201, 2012). On the other hand, the need is raised to study the vulnerability of existing buildings, which can be divided into the buildings designed to resist the gravity loads only (GLD) and the buildings designed according to Egyptian code (EC-1994). Comparison between forces due to Egyptian code for loads (EC-1994) and (ECP-201, 2012) is carried out on the multi-stories R.C. framed buildings which are the most common type of existing buildings in Egypt. To investigate the vulnerability of existing buildings, nonlinear static pushover analysis is conducted to evaluate the real strength of the existing buildings. Moreover, it is considered a useful and effective tool for the performance of three framed buildings: 3, 6 and 10 stories due to expected future earthquakes. Finally, it is found that the vulnerability of existing GLD buildings occurs at expected ground accelerations (ag) greater than 0.125 g in Egyptian seismic map, while the EC-94 designed buildings behave elastically up to (ag) equals to 0.2 g and above that a slight damage may occur.