Seismic Performance Assessment of a Multistoried Building and Retrofitting of RC Columns

Earthquake is a major concerned natural disaster that causes great damage to the structure. Many multistoried commercial, factory and also residential building in Bangladesh are not designed properly considering seismic loads and also seismic zone effects, thereby large storey displacement and cracks have been observed in the structures. In the present study, a G+10 storied factory building is considered and finite element analysis software ETABS 2015 is used to determine the seismic demand and capacity of each structural element considering seismic zone 1 and zone 3. The building is preliminary designed and analyzed for zone 1 and found safe against seismic loads but vulnerable at zone 3. In the developing countries like Bangladesh, RC jacketing method is popular due to its cost effectiveness comparing with other strengthening methods. Therefore, in this study, a guideline for strengthening of columns only by RC jacketing method is discussed and analyzed. The columns having Demand Capacity Ratio (DCR) ratio more than 1.0 found from analysis are considered to strengthen. Pushover analysis is done to determine the performance of the structure before and after retrofitting and it is found that structure after retrofit have more base shear and displacement capacity, and less storey drift compared to unretrofitted structure.