International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 07 | July-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 2273 Non-Linear Static Analysis of G+6 Storey Buildings With and Without Floating Columns by Provision of Infill Walls Using User-Defined Hinges Suneelakumar Hattarakihal 1 , Dr.S.S.Dyavanal 2 1 Post Graduate Student, BVBCET, Hubli, Karnataka, India 2 Professor, BVBCET, Hubli, Karnataka, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract – The floating columns are given the priority in the multi-storey structures, as to cope up with the problems with continuing the columns from a lower storey, due to the disturbance caused by them to usable area and aesthetics. In the present study, performance based seismic evaluation of 3D G+6 storeys RC building with and without floating columns is carried out. The building models located on medium soil in seismic zone III, are considered. Brick masonry and solid concrete block infill walls are modelled as equivalent diagonal strut. Two distinct analyses are carried out namely, equivalent static and response spectrum as per the load combinations given in IS 1893 (Part I) 2002 using ETABS 2013 V13.2. All the building models are designed as per IS: 456-2000 and their performance based seismic investigation is assessed by pushover analysis considering FEMA 440 parameters. The pushover results like hinge status, ductility ratio, safety ratio and global stiffness are compared for different models. Key Words: Floating column, Infill, Pushover Analysis, User defined hinges, Ductility ratio, Hinge status, Global stiffness, Safety ratio 1. INTRODUCTION The floating columns or hanging columns are also vertical members similar to normal RC columns. The hanging columns are normally constructed above the ground storey, so that the ground storey can be utilized for the parking, play ground, and function halls. These floating columns disturb the uniformity of distribution of loads in the buildings, thus leading to more flexibility and there by weakening the seismic resistance of building shown in figure1. Building with floating columns is constructed to take advantage of urban bylaws. As per urban bylaws, a pre- specified space should be left open between all sides of the building and the plot boundary. The building with floating columns have both in- plane and out-of-plane irregularities in strength and stiffness and hence are seismically vulnerable. This type of construction does not lead to any problem under the conditions of vertical loading. But during earthquake a clear load path is not available for transferring the lateral forces to the foundation. Lateral forces accumulated in the upper floors during the earthquake have to be transmitted by the projected cantilever beams. Overturning forces thus developed overwhelm the columns of ground floor. Under this situation the columns tend to deform and buckle, resulting in total collapse. Therefore there is a need to understand the seismic behaviour of such building and to retrofit the existing buildings with floating columns so that they can withstand further probable earthquake generated forces. Fig-1: Building with floating column [23] 1.1 Objective of Study The objective of this work is to evaluate through an analytical study, the seismic performance of three dimensional seven storey symmetric multistory RC buildings with and without floating columns. Following are the main objectives of the study:  To study nonlinear static behaviour of multistorey building with and without floating columns.  To study the seismic behaviour of floating column with the provision of infill  To study the performance parameters like hinge status, ductility ratio, safety ratio and global stiffness.