Seismic performance and strengthening of tall reinforced concrete building: a case study

Tall reinforced concrete buildings are increasingly becoming popular due to the rising housing demand and scarcity of space. These buildings need specific consideration with respect to the design and detailing. Most importantly, the dynamic behaviour and seismic damage of these buildings are considerably different compared to low- and mid-rise structures. Damaged or seismically deficient buildings can be restored with a suitable strengthening strategy, however, a pre-assessment of the lateral load behaviour of these buildings is necessary. Presently, seismic strengthening measures based on nonlinear analysis are abundant, and each of them is used according to the need or the damage level incurred in the structure or its components. However, seismic strengthening based on visible cracks or damage in the building, followed by a linear analysis to assess its performance level is also in practice. The present study is motivated towards the seismic assessment and rehabilitation of one such case study 15-storied reinforced concrete building that was hit and damaged by the M7.8 Gorkha earthquake on 25 April 2015 in Nepal. Optimal strengthening strategies for the building are suggested based on the overall improvement in its seismic performance and damage probability through nonlinear analyses.