Seismic Resilience of Beam-to-Beam Connected RC Buildings: A Comparative Study with Conventional Frames

Abstract

This study presents a comprehensive comparative analysis of the seismic performance between conventional Reinforced Concrete (RC) moment frames and innovative beam-to-beam connected RC structural systems. With increasing architectural complexity in modern construction, alternative connection methodologies are being explored for their potential advantages in design flexibility and construction efficiency. The research evaluates two prototype buildings a 3-span and 4-span structure designed according to BNBC 2020 provisions for seismic Zone 2 (Z=0.12) in Rajshahi, Bangladesh. Both structural systems were analyzed using equivalent static analysis methods to assess key seismic performance parameters including inter-story drift ratios, lateral stiffness characteristics, displacement profiles, overturning moments, and story shear distributions. The conventional RC frame with standard beam-column connections serves as the baseline model, while the alternative system incorporates direct beam-to-beam connections at specific locations. Material properties were maintained consistent across both systems, featuring 3000 psi concrete for beams/slabs, 3500 psi for columns, and Grade 60 reinforcement. Results indicate that the beam-to-beam connected system exhibits 4–12% higher inter-story drifts and marginally increased displacement demands (1.5–2.1%) compared to conventional frames, suggesting reduced lateral stiffness. However, critical load-resisting mechanisms including overturning moments and story shear capacities showed negligible variations (<0.5%), indicating comparable strength characteristics. These findings provide valuable insights for structural engineers considering alternative connection configurations in moderate seismic regions, highlighting both the potential benefits and necessary design considerations for implementing beam-to-beam connections in RC frame structures.