Seismic Response Analysis of High-Rise Buildings Using Base Isolation Techniques

Abstract

High-rise buildings located in seismically active regions are highly susceptible to earthquake-induced forces that can lead to severe structural damage and loss of life. Conventional fixed-base structures often experience large lateral displacements and high inter-story drifts during seismic events. Base isolation techniques have emerged as an effective structural control strategy to mitigate seismic forces and improve building safety and performance. This study presents a seismic response analysis of high-rise buildings incorporating base isolation systems to evaluate their effectiveness in reducing structural vibrations. The methodology involves the development of numerical models of high-rise buildings using finite element analysis, considering both fixed-base and base-isolated configurations. Common isolation devices such as lead rubber bearings (LRB) and friction pendulum systems (FPS) are modeled to simulate realistic seismic isolation behavior. Time-history analysis is conducted using real earthquake ground motion data to assess structural response parameters including base shear, displacement, acceleration, and inter-story drift. The results indicate that base isolation significantly reduces seismic forces transmitted to the superstructure, resulting in improved structural performance and enhanced occupant safety. A substantial reduction in base shear and floor acceleration is observed in isolated structures compared to conventional fixed-base systems. It is also found that base isolation effectively shifts the natural frequency of the structure, thereby minimizing resonance effects during seismic excitation. The study concludes that base isolation techniques provide a highly efficient solution for improving the seismic resilience of high-rise buildings.