Pushover Analaysis of Irregular Tall RCC Structures

Abstract

The paper is based on the study of the Response of Irregular Plan Tall RCC structures by Pushover Analysis in order to find the Base Shear, Pushover Curve, Performance limit, Shear force Diagrams, Bending Moment of the structure. Nonlinear Static Analysis, is also called as “pushover analysis”, and is also regarded as the most widely used analysis method for estimation of performance of Irregular tall RCC structures. Most of the significant Seismic Codes which proposes methods for seismic analysis of new or existing tall RCC Structures have been originally defined for simple regular structures. Therefore the analysis of the seismic response of irregular Tall RCC Structures is difficult due to nonlinear and inelastic response of the structures and more difficult than that of regular structures. Most of the codes (IS 1893 (Part 1) 2016[1], ATC-40 1996[2], EC8-1 2004[3]) uses the concept of “regularity”, taking into account distribution of mass, stiffness and strength in the structures, both in plan and in elevation. But real structures seldom act in accordance with these regularity requirements, resulting in a narrowly dependable application of the basic non-linear static analysis. For the study we are considering two G+19 storey T shaped and U shaped irregular tall framed RCC structures having height of 68 meters each and storey height of 3.3 meters. Pushover Analysis is carried out using shear walls at different locations in the structure. The objective of this study is to finds out which irregular plan tall structure is the most efficacious in resisting lateral loads. The software used for modelling and analysis is ETABS 2017.