A Review on the Effectiveness of Base Isolation Systems in Improving Seismic Performance of RCC Structures

Abstract

Reinforced concrete buildings designed with conventional fixed-base assumptions often experience considerable seismic forces, leading to structural and non-structural damage during strong earthquakes. To address this issue, base isolation has been developed as an advanced seismic control technique that aims to reduce the direct transmission of ground motion to the superstructure and thereby minimize seismic demand. This review paper critically examines and synthesizes research studies that investigate the seismic performance of base-isolated RCC buildings in comparison with traditional fixed-base structures. The review emphasizes key seismic response indicators such as base shear, lateral displacement, inter-storey drift, floor acceleration, natural time period, and overall energy dissipation characteristics. Various analytical methodologies employed by researchers, including response spectrum analysis and nonlinear time history analysis, are thoroughly evaluated to understand their effectiveness in capturing the dynamic behaviour of isolated systems. Particular attention is given to the performance of lead rubber bearing isolators, which are widely adopted due to their combined flexibility and damping capabilities. The collective findings of the reviewed literature demonstrate that base-isolated RCC buildings generally show a notable reduction in seismic forces and structural damage when compared to fixed-base buildings, while improving displacement control and occupant safety. Nevertheless, the effectiveness of base isolation depends on appropriate design, site conditions, and seismic characteristics. This review outlines significant findings concerning the advantages and limitations of base isolation systems, thereby providing a comprehensive understanding of their role in seismic risk mitigation.