Influence of Staircase Configuration on the Dynamic Behavior of Tall Residential RCC Buildings Under Seismic Loading

Staircases are critical structural and functional components of reinforced concrete (RCC) buildings, serving as both vertical circulation systems and essential evacuation routes during seismic events. Due to their relatively high stiffness and interaction with surrounding beams, slabs, and columns, staircases significantly influence the dynamic behavior of buildings by affecting lateral load distribution, natural time period, base shear, storey displacement, and inter-storey drift. Different staircase configurations, such as waist slab, dog-legged, open-well, cantilever, and helical staircases, exhibit distinct seismic responses, while previous studies have highlighted their effects on stiffness variation, torsional behavior, short-column action, and localized damage near landings. However, limited research has been conducted on tall RCC buildings, comparative performance of staircase types and locations, and their behavior under varying seismic zones and structural parameters. To address these gaps, the present study investigates the influence of staircase type, location, and building height on the seismic performance of tall RCC residential buildings using ETABS software. Multiple analytical models with and without staircases are developed and analyzed through the response spectrum method in accordance with relevant seismic design provisions. The study further considers variations in staircase arrangements, seismic zones, concrete grades, member sizes, and wind loading effects, while evaluating key dynamic parameters such as natural time period, base shear, mass participation, storey displacement, and inter-storey drift. The findings aim to enhance the understanding of staircase–structure interaction and emphasize the importance of accurate staircase modeling and seismic-resistant detailing for improving the safety, stability, and overall performance of tall RCC residential buildings.