International Research Journal of Education and Technology

High-rise buildings often contain basements, which are often assumed in structural analysis to be at a fixed ground level. However, basements introduce flexibility, leading to larger lateral displacements, longer vibration periods, and even changes in seismic response. For example, a 20-story building with a basement had a roof displacement of 13.8 cm compared to 12.7 cm without the basement, and its vibration period increased by 10%. Seismic loads also influence member forces in basements, and their consideration in structural analysis is necessary for accuracy. A matrix condensation procedure, which employs rigid diaphragms to reduce degrees of freedom in basement floors, has been proposed to address this issue effectively. In India, many G+15 reinforced concrete (RC) structures are constructed in high seismic zones without adherence to seismic coal provisions. This lack of compliance poses great risks to occupants, as earthquakes often expose the vulnerabilities of inadequately designed structures. The most common failure mechanism in such buildings is the soft story sway mechanism, where insufficient column strength causes large lateral displacements.