Study on Seismic Capacity Assessment of Existing RC Building by Using Pushover Analysis

The infrastructure, existing in Sudan, is mostly not structured or designed to resist seismic forces
accordingly. The study investigated the seismic damage of a 5 storey existing reinforced concrete
building in Khartoum, Sudan. Three performance levels were considered in the study, which included
immediate occupancy, life safety, and collapse prevention. The gravity push was carried out using
force control method and lateral push with displacement control, using SAP2000. Pushover analysis
produces push curve, consisting of capacity spectrum, demand spectrum, and performance point. It
showed the performance level of building components along with maximum base shear carrying
capacity. It has been observed that demand curve intersected the capacity curve between the points
B and C at the X direction that is life safety level; and between the points B and C at the Y direction
that is life safety and collapse prevention level. Therefore, some building elements are needed to be
strengthened. The study concluded that pushover analysis is preferably used for static nonlinear
procedures because of its simplicity. It has been observed that the location of plastic hinges indicated
weak zones in a building, which is helpful for re-strengthening the existing buildings. It has been
analyzed that the building can be easily stiffened or strengthened by changing member properties and
rerunning the analysis.