Seismic Performance of Indian RC Tall Buildings with Transfer Beam Located in Lower Seismic Zone (II)

Abstract - The seismic performance of reinforced concrete (RC) tall buildings with transfer beams has become a subject of growing interest, particularly in the context of Indian urban development. Transfer beams are often introduced in high-rise buildings to accommodate architectural or functional requirements, such as parking or commercial spaces in the lower levels. However, their inclusion leads to vertical irregularities that may compromise the building’s response during seismic events. While buildings in Seismic Zone II of India are subjected to relatively low seismic forces, the presence of such irregularities necessitates closer scrutiny to ensure structural safety and serviceabilityThis study evaluates the seismic behavior of a 18-storey RC building with a transfer beam at the fourth level, designed as per Indian Standards IS 456:2000 and IS 1893 (Part 1):2016. Using structural modeling and nonlinear analyses (pushover and time-history), the study compares the performance of buildings with and without transfer beams under Zone II ground motions. Results indicate increased inter-story drift, concentration of plastic hinges, and reduced energy dissipation capacity in the structure with the transfer beam. These findings suggest that even in lower seismic zones, the inclusion of transfer elements can significantly affect seismic performance, underscoring the need for performance-based design approaches. The structural behavior of reinforced concrete (RC) tall buildings during seismic events is critically influenced by the presence of transfer beams, especially in configurations where architectural and functional requirements dictate column discontinuities. In lower seismic zones like Zone II of the Indian Seismic Code (IS 1893:2016), the design considerations may not fully address the complex dynamic response induced by such irregularities. This study investigates the seismic performance of RC tall buildings with transfer beams located at podium or mid-levels through detailed nonlinear time history and pushover analyses. Various models with different transfer beam configurations were developed and evaluated using seismic data representative of Zone II conditions. The results indicate that while the base shear and inter-storey drift remain within permissible limits, the presence of transfer beams introduces localized stress concentrations and stiffness irregularities. The study highlights the need for more refined design guidelines, even in low seismic zones, to ensure adequate performance and safety of tall RC structures. Keywords: Reinforced Concrete (RC), Tall Buildings, Transfer Beam, Seismic Performance, Seismic Zone II, IS 1893:2016, Structural Irregularity, Nonlinear Analysis, Time History Analysis, Pushover Analysis