Retrofitting the seismically deficient structures before earthquakes provides a feasible approach to
improve their load carrying capacity and reducing their vulnerability. This study presents an
analytical assessment investigation on hollow block slab reinforced concrete building. The building
is not designed according to seismic standards; moreover, hollow block slab systems may lack the
sufficient lateral seismic resistance. Different retrofitting systems to enhance the seismic capacity of
the target building are proposed and evaluated. These systems include strengthening the columns
with reinforced concrete jackets or using internal shear walls or introducing steel chevron bracing.
The target building before and after retrofitting is analyzed either as bare frames or considering
masonry infill walls with different parameters. The three dimensional nonlinear pushover analysis
procedures are used in evaluating the seismic performance of the original building and the retrofitted
ones. The demand response spectra proposed by the Egyptian Code of Loads, ECOL 201, 2012
edition, for different seismic zones with different soil properties are utilized in the evaluation. Real
seven earthquakes response spectra with maximum-scaled spectrum acceleration close to the one
calculated for Cairo city are also applied. It is found that the original target building, before
retrofitting, fails to fulfill the demands of neither many of the ECOL response spectra nor many of
the applied real earthquakes. All the proposed retrofitting systems succeed in highly enhancing the
seismic capacity of the original building. Considering masonry infill walls in the analysis has a
crucial role on the seismic performance of the original building, the retrofitting systems can, due to
the increase in the lateral strength, limit this effect.