Second Order or P-Delta Effects in Tall Structures

Tall building structures are in practice now a days. Due to the frequent earthquakes happening around the world, these buildings need to be designed Earthquake resistant. The second order effect or P-delta effect has to be included in the analysis since the deflections are generally large for tall building structures. The objective of the current work is to study is to the influence of second order or P-Delta effect in the structural behaviour of tall building structures. Alternative lateral load resisting systems i.e. OMRF (Ordinary moment resisting system), SMRF (Special moment resisting system), Shear wall system and Bracing system for the tall building structures are considered. For this purpose 5, 10, 15 and 20 story structures are modelled and analysed using ETABS software and using the Indian Standard Codes for analysis and design namely, IS 1893:2002, IS 456:2000. The buildings modelled are with floor area of (20m x 20m) with 4 bays of 5m span along both directions.