Seismic Performance and Structural Capacity Assessment of a Ten-Story Reinforced Concrete Building Using Nonlinear Static Pushover Analysis

Abstract

The seismic performance of reinforced concrete buildings depends on adequate member strength and the ability of the structural system to sustain lateral deformation beyond the elastic range. This study aims to assess the structural capacity and seismic performance of a ten-story reinforced concrete building through linear structural evaluation and nonlinear static pushover analysis. The assessment includes modal characteristics, mass participation, base reactions, interstory drift, beam and column capacity, pushover capacity curves, plastic-hinge development, and structural performance levels in the X and Y directions. Twelve vibration modes are considered, with cumulative translational mass participation reaching 94.13% in the X direction and 94.08% in the Y direction. The beam capacity evaluation gives a nominal flexural strength of 186.96 kN·m compared with a factored moment demand of 64.92 kN·m. The evaluated column has a reduced axial strength of 6407.29 kN against an axial demand of 1627.27 kN. Nonlinear static analysis shows that the maximum base shear reaches 17,110.19 kN at a roof displacement of 0.715 m in the X direction and 16,301.71 kN at 0.699 m in the Y direction. The X-direction lateral capacity is therefore approximately 5.0% higher than that in the Y direction. Plastic hinges progressively develop as lateral displacement increases, primarily within the lower and intermediate stories. The ATC-40 capacity-spectrum evaluation classifies the structural performance in both principal directions as Damage Control (SP-3), between Immediate Occupancy and Life Safety. The combined strength and nonlinear-response results indicate that the investigated building maintains adequate member capacity and lateral resistance at the evaluated seismic performance point, although the directional difference in stiffness and nonlinear response should be considered in the interpretation of its seismic behavior.