Recommendation for Effects of Floating Column in Different Seismic Zones: A Review

Floating columns have become quite popular in India's urban development over the last decade, especially in commercial-residential buildings. The main reason is simple architects, developers want to open retail spaces on the ground floor and floating columns let them achieve that. While this sounds great from a business perspective, structural engineers have realized it comes with some serious challenges during earthquakes. Floating columns make buildings significantly more flexible, increasing natural vibration time periods by 5-27%. This increased flexibility means that buildings sway more during earthquakes by about 25-40% even more than normal buildings. Storey drift, which is the movement of floors from one to the next, increases by 20 to 35%. The most important thing is how the problem gets worse as you go to areas with a higher risk of earthquakes. Floating columns can work in areas with low risk if you plan carefully. But in high-risk seismic zones they become a serious concern. In Zones IV and V especially heavy strengthening with shear walls and special transfer beams, and many experts now recommend just avoiding them altogether in those zones. This review gives practical advice to engineers who need to decide whether floating columns make sense for a project.