Seismic Performance Evaluation of RC Buildings: A Comparative Study of Non-Engineered vs. Code-Based Designs

This study investigates the seismic vulnerability of non-engineered reinforced concrete (RC) buildings compared to codel-based structures. The research uses linear elastic and nonlinear pushover analyses to evaluate critical seismic performance parameters such as natural periods, mass participation, base shear, capacity curve, ductility ratio, overstrength factor, collapse mechanics, and nonlinear hysteretic damping. Structures designed following standards like NBC 205 (old), RUD 205 new, and IS 1893 are analyzed against non-engineered building samples (NES1–NES6) to highlight performance gaps.

The findings reveal that code-compliant buildings demonstrate significantly higher seismic resistance, greater flexibility, effective earthquake energy dissipation, higher ductility, overstrength factor, and base shear capacity. Non-engineered buildings often exhibit soft-story failure, with initial damage observed in the columns, highlighting their vulnerability during seismic events. Meanwhile, engineered RC buildings (RUD) designed with seismic principles demonstrate better seismic performance, adhering to the "strong column, weak beam" philosophy and superior strength-to-capacity ratios, higher overstrength factors, and enhanced ductility ratios, highlighting their resilience under seismic loads.

These results indicate the critical need to adopt and enforce seismic design codes and retrofit vulnerable buildings to enhance earthquake safety. The results conclude that addressing the code provisions ensures earthquake-resistant buildings with warranted ductile behavior for structural systems, enabling the achievement of the intended collapse mechanism.