A Comprehensive Review on Seismic Performance of Regular and Irregular Reinforced Concrete Structures.

The seismic response of reinforced concrete (RC) buildings is largely governed by their overall geometry, the distribution of stiffness and mass, and the degree of structural regularity. Buildings with a regular layout generally exhibit a uniform and predictable behavior when subjected to earthquake loading, whereas irregular structures often experience complex dynamic effects such as torsional rotations, concentration of stresses at discontinuities, and amplified inter-storey drifts. This review paper provides a comprehensive evaluation of previous studies examining both plan and vertical irregularities in RC buildings. It synthesizes research findings published between 2004 and 2021, offering a comparative understanding of how irregular configurations influence seismic parameters like lateral displacement, storey drift, and base shear. Analytical techniques such as the Response Spectrum and Time History methods have been widely employed across these studies to quantify the structural response. The collective results indicate that irregular buildings can experience approximately 40–60% greater lateral displacement and 25–35% higher base shear than their regular counterparts. The paper further identifies key parameters that contribute to these variations—such as abrupt changes in geometry, stiffness discontinuities, and mass eccentricities—and discusses their implications with respect to current seismic design codes. Finally, it emphasizes the need for refined modeling approaches and improved design strategies to enhance the seismic resilience and safety of geometrically irregular RC structures.