International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 04 | April-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 1749 Study of the effect of base isolation on flat slab building for multi- storey building in seismic prone areas Kamei Gaibaulung 1 , S.A.Vengadesh Subramanian 2 1 Student, Structural Engineering, SRM University, Chennai, 2 Assistant Professor, Civil Engineering Department, SRM University ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - The main aim of using seismic base isolation tool is to reduce the inertial forces introduced in the structure by shifting the fundamental period of the structure out of dangerous resonance range and concentration of the deformation demand at the isolation system. In the paper a parametric study on Reinforced Concrete building and flat plate building with fixed base and isolated base with rubber bearing are carried out using response spectrum method. Here, the design spectra recommended by Indian Standard Code IS 1893-2002 (part-1) is considered for comparison. The main objective of this study is to investigate the differences in the dynamic analysis of G+4, G+8 and G+10 RC building and Flat plate building with fixed and isolated base condition. To evaluate the seismic response of the buildings, elastic analysis is performed using the computer finite element program SAP2000. From the analysis, it is found that the time period and top displacement are more in flat plate building with base isolator compared to other models. The base shear is reduced in flat plate building compared to other models. Key Words: Reinforced Concrete Frame, Flat Plate Frame, SAP 2000, and Response Spectrum Analysis. 1.INTRODUCTION The traditional method, i.e., strengthening the stiffness, strength, and ductility of the structures, has been in common use for a long time. Therefore, the dimensions of structural members and the consumption of material are expected to be increased, which leads to higher cost of the buildings as well as larger seismic responses due to larger stiffness of the structures. Thus, the efficiency of the traditional method is constrained. To overcome these, many vibration-control measures called structural control, have been studied and remarkable advances in this respect have been made over recent years. Structural Control is the one of the areas of current research aims to reduce structural vibrations during loading such as earthquakes and strong winds. In terms of different vibration absorption methods, structural control can be classified into active control, passive control, hybrid control, semi-active control and so. Base isolation is a passive vibration control system that does not require any external power source for its operation and utilizes the motion of the structure. Performance of base isolated buildings in different parts of the world during earthquakes in the recent past established that the base isolation technology is a viable alternative to conventional earthquake-resistant design of medium-rise buildings. The application of this technology may keep the building to remain essentially elastic and thus ensure safety during large earthquakes as they decouples the structure from the horizontal components of the ground motion and reduces the possibility of resonance. This decoupling is achieved by increasing the flexibility of the system, together with appropriate damping by providing isolator at the basement level of the structure. 2. OBJECTIVE OF WORK The main objective of this study is to investigate the differences in the dynamic analysis of G+4, G+8 and G+10 RC building and Flat plate building with fixed and isolated base condition by comparing the responses such as time period, base shear and top displacement by using response spectrum analysis. 3. DESCRIPTION OF BUILDING In the present work G+4, G+8 and G+10 storey regular plan buildings situated in zone V, are considered. For the study RC frame and flat plate frame are taken with fixed base and with base isolator. This study includes modelling and analysis of the models by using standard FEA package Software SAP 2000. Material properties and section properties are defined and assigned. Reinforced concrete frame elements are modelled as beam and column elements. Slab is modelled as an area element. Response spectrums are performed on models. For this study, 12 building models are considered for the comparison. The characteristics of the isolators used are selected from the available or producible products in the light of the information obtained from the manufacturers. While deciding about the isolator characteristics; the characteristics of the device, which subject the structure to minimal effects, while themselves are displacing within