Journal of Civil Engineering and Environmental Technology p-ISSN: 2349-8404; e-ISSN: 2349-879X; Volume 3, Issue 5; April-June, 2016, pp. 452-457 © Krishi Sanskriti Publications http://www.krishisanskriti.org/Publication.html Performance Evaluation of Flat Slab with Modified Storey Height using Pushover Analysis Sayali A. Baitule 1 and Ashish R. Akhare 2 1 PG Student, Department of Applied Mechanics, Government College of Engineering Amravati 444604, Maharashtra, India 2 Department of Applied Mechanics, Government College of Engineering Amravati 444604, Maharashtra, India E-mail: 1 sayali.baitule@gmail.com, 2 ashishakhare@gmail.com Abstract—Flat slab buildings are becoming popular from architectural and aesthetic point of view and construction of flat slab building is increasing rapidly as they have many advantages. But performance of flat slab building in high seismic zone is poor. Large or small ground storey height is very common feature in the multistory construction. Now a day, According to the demand of structure, large or less storey height can be seen on any other floor. In the present study, performance of flat slab building with an effect of modified storey height at various stories is evaluated by using non- linear static pushover analysis. Pushover analysis is performed by using ETABS software. Results are obtained in the form of capacity curve, performance point and plastic hinge mechanism for models having modified storey height at various floors. The results are compared and the best position for storey having large or less storey height is suggested. 1. INTRODUCTION” 1.1 Flat Slab The flat slab is an American development, originated by Turner in 1906 [5]. Flat slab is a slab which is directly supported on columns without beam. In such slabs, large shear forces and bending moments are induced in vicinity of columns. Therefore the columns are flared at the top called column head or column capitals and slabs are thickened surrounding the column capitals called drops for reducing stresses due to moments and shears. In some cases the drop in the flat slab is omitted when moments and shears in the slab surrounding the column head are not excessive and can be resisted by the slab without extra thickening. Often the column head is omitted and only drop is provided. When the span of slab is not large and loads are not excessive, both drop and column head may be omitted. Such type of flat slab is known as flat plate [3]. Based on these needs of structure the flat slabs can be divided into following types. a) Flat slab with drop panel and without column capital. b) Flat slab with column capital and without drop panel. c) Flat slab with drop panel and column capital. d) Flat slab without drop panel and column capital. Fig. 1: Types of flat slab 1.2 Pushover Analysis The pushover analysis i.e. non-linear static analysis of a structure is a procedure in which series of incremental static analysis carried out to develop a capacity curve for building. The building is subjected to a lateral load. The load magnitude increases until the building reaches target displacement. This target displacement is determined to represent the top displacement when the building is subjected to design level ground excitation. Fig. 2 illustrates pushover analysis [4]. The pushover analysis generates the relationship between base shear (V) and roof displacement (∆ roof ) which is known as pushover curve or capacity curve. The capacity curve and demand curve are plotted in the Acceleration Displacement Response Spectrum (ADRS) format which is having spectral displacement along horizontal axis and spectral acceleration