Study on existing reinforced concrete buildings seismic vulnerability after retrofitting

The present study focusses on retrofitting of the seismically deficient gravity designed existing RC buildings. Four RC buildings which is existing in India were taken for this analysis. All the structures are subjected to Non-linear Static Pushover(PO) and Dynamic Time History(TH) Analysis using SAP 2000 to check the capacity of structures under seismic loads. The plastic hinges are assigned as per the guidelines of FEMA 356 in. Pushover analysis. Elcentro Ground motion is used for dynamic analysis. The comparison is made between Pushover and Time History Analysis to check how closely the Pushover analysis estimates the dynamic response of the structure. The analysis showed damages in all the buildings with formation of hinges above Collapse Prevention (CP) level. Also, the interstorey drifts of all the buildings exceeded the drift limit as per IS1893. Hence, each building is retrofitted with different suiTABLE retrofitting techniques. Further, the retrofitted buildings are subjected to the Non-linear Static Pushover and Dynamic Time History Analysis and compared with the unretrofitted buildings to check the resilience of the structure under seismic loads.