PERFORMANCE BASED PUSHOVER ANALYSIS OF R.C.C FRAMES FOR PLAN IRREGULARITY Dr. MOHD. HAMRAJ Professor, Civil Engineering, MJ College of Engineering and Technology, Telangana, )ndia, Email: hamrajͷ͸͹@gmail.com ABSTRACT A performance‐based Analysis is aimed at controlling the structural damage based on precise estimations of proper response parameters. Performance‐based seismic design explicitly evaluates how a building is likely to perform; given the potential hazard it is likely to experience, considering uncertainties inherent in the quantification of potential hazard and uncertainties in assessment of the actual building response. )t is an iterative process that begins with the selection of performance objectives, followed by the development of a preliminary design, an assessment as to whether or not the design meets the performance objectives, and finally redesign and reassessment, if required, until the desired performance level is achieved. )n this present study three new R.C.C buildings unsymmetrical in plan ȋL‐shapeȌ ȋdesigned according to )S Ͷͷ͸:ʹͲͲͲȌ is taken for analysis: Ͷ, ͺ and ʹͲ storey to cover the broader spectrum of low rise, medium rise & high rise building construction. Different modeling issues were incorporated through six model for each building were; bare frame ȋwithout infillȌ, having infill as membrane, replacing infill as an equivalent strut in previous model. The pushover analysis has been carried out using ETABS. Buildings located in Zone‐))) have been analyzed Comparative study made for bare frame ȋwithout infillȌ, having infill as membrane, replacing infill as an equivalent strut. The results of analysis are compared in terms of Base Shear, Storey Displacement and Drift Ratio. The buildings were designed to meet the performance level, whose damage is limited to Grade ʹ ȋslight structural damage, moderate nonstructural damageȌ in order to enable )mmediate Occupancy, is termed as Performance Based Design. For seismic performance of reinforced concrete buildings, Capacity Spectrum Method ȋCSMȌ is used. Index Terms: Response, Base Shear, Storey Displacement and Drift Ratio. 1. INTRODUCTION 1.1 General Amongst the natural hazards, earthquakes have the potential for causing the greatest damages since earthquake forces are random in nature & unpredictable, the engineering tools needs to be sharpened for analyzing structures under the action of these forces. Performance based design is gaining a new dimension in the seismic design philosophy wherein the near field ground motion ȋusually accelerationȌ is to be considered. Earthquake loads are to be carefully modeled so as to assess the real behavior of structure with a clear understanding that damage is expected but it should be regulated. )n this context pushover analysis which is an iterative procedure shall be looked upon as an alternative for the orthodox analysis procedures. This study focuses on pushover analysis of multistory RC framed buildings subjecting them to monotonically increasing lateral forces with an invariant height wise distribution until the preset performance level ȋtarget displacementȌ is reached. 1.2 Need of Performance Based Seismic Design From the effects of significant earthquakes, it is concluded that the seismic risks in urban areas are increasing and are far from socio‐economically acceptable levels. There is an urgent need to reverse this situation and it is believed that one of the most effective ways of doing this is through, the development of more reliable seismic standards and code provisions than those currently available and their stringent implementation for the complete engineering of new engineering facilities. A performance‐based design is aimed at controlling the structural damage based on precise estimations of proper response parameters and the flow diagram is shown in Figure ͳ.ʹ. Figure 1.2 Performance‐based design flow diagram 1.3 Objectives i. To evaluate the effect of masonry wall for low, medium and high rise building in terms of Top Storey Displacement. ii. To study the load carrying capacity of different frames ȋconsidered in this workȌ using masonry wall as infill and equivalent diagonal strut in terms of Base Shear at performance point. 1.4 Scope of the Present Study The scope of present study aims at evaluation of R.C buildings ȋdesigned according to )S Ͷͷ͸:ʹͲͲͲȌ using Dr. MOHD. HAMRAJ et al. DATE OF PUBLICATION: OCT 19, 2014 ISSN: 2348-4098 VOLUME 2 ISSUE 7 SEP-OCT 2014 INTERNATIONAL JOURNAL OF SCIENCE, ENGINEERING AND TECHNOLOGY- www.ijset.in 1544