ISSN(Online) : 2319-8753 ISSN (Print) : 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 5, Special I ssue 9, May 2016 Copyright to IJIRSET DOI:10.15680/IJIRSET.2016.0505502 9 A Performance Based Evaluation of a Wall- Frame Structure Employing the Pushover Analysis Tool Kiran Kamath 1 , Jose Camilo Karl Barbosa Noronha 2 , Sachin Hirannaiah 3 Professor, Dept. of Civil Engineering, Manipal Institute of Technology, Manipal University, Karnataka, India 1 PG Student, Dept. of Civil Engineering, Manipal Institute of Technology, Manipal University, Karnataka, India 2 PG Student, Dept. of Civil Engineering, Manipal Institute of Technology, Manipal University, Karnataka, India 3 ABSTRACT: In this study a performance based assessment of 2D concrete shear wall-steel framed structures subjected to 3 lateral load patterns has been made. The nonlinear behaviour has been carried out using default plastic hinges in accordance with ASCE41-13. The analysis has been carried out on structures with varying aspect ratio accompanied with a varying elastic lateral stiffness ratio of the shear wall with respect to the frame. Structures subjected to a uniform lateral load pattern exhibited a larger base shear and lower roof displacement at performance in comparison with its first mode shape and code specified lateral load pattern. KEYWORDS: Stiffness Ratio, Load Pattern, Performance. I. INTRODUCTION The Indian sub-continent is no stranger to earthquakes due to the rate at which the Indian plate is driving into Asia. This makes 54% of our land vulnerable to earthquakes and it is this statistic that makes earthquake engineering vital. Most building codes give us a linear method of analysis for earthquake loads although it is an established fact that structures move into a nonlinear behaviour during an earthquake activity and hence these linear methods fail to give us an estimate of the building demands during an earthquake. With the advent of performance based design of structures, nonlinear behaviour of structures is given more importance and this technique helps us better understand the seismic demands on a structure. The nonlinear static pushover procedure can be considered as a simplified non-linear analysis method in which the dynamic load is substituted by a gradually increasing (static) lateral load. II. RELATED WORK The nonlinear static pushover analysis has multiple purposes besides a performance based evaluation of a structure. It is used to evaluate/verify the overstrength ratio values used to calculate the response reduction factor of a structure (A. Mondal et al. [1], D. M. Patil, K. K. Sangle [2] and M. Izadinia et al. [3]). It is used to estimate the plastic mechanisms and distribution of damage in a structure during seismic activity. It is used to assess the structural performance of existing or retrofitted buildings (Ismail [4]). III. DESCRIPTION OF MODELS All models considered in this study are 2D wall-frame structures comprising of 3 bays (Fig.1). The bay width has been adjusted in the models in order to attain the required elastic lateral stiffness ratio of the concrete shear wall (K SH ) with respect to the steel frame (K SF ). For simplicity, the models have been assumed to be fixed at the base. The aspect ratio (height of the structure with respect to its base width) has been varied from 2.0 to 4.5 in steps of 0.5 by keeping the base width constant at 12 m and varying its height. The stiffness ratio is varied from 0.5 to 3.5. Grade of steel used is Fe250 whereas the concrete grade varies with the aspect ratio. Typical storey height is assumed to be 3m.