International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 05 Issue: 01 | Jan-2018 www.irjet.net p-ISSN: 2395-0072 © 2018, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 404 ANALYSIS OF THE BASE ISOLATED BUILDING (LEAD PLUG BEARING) IN ETABS 1 PG Scholar, Department of Civil Engineering, GEC, Jagdalpur, Chhattisgarh, India 2 Assistant Professor, Department of Civil Engineering, GEC, Jagdalpur, Chhattisgarh, India 3 Professor & Principal, Department of Civil Engineering, GEC, Jagdalpur, Chhattisgarh, India -------------------------------------------------------------***------------------------------------------------------------- Abstract - The present work attempts to study the effectiveness of base isolation using lead rubber bearings (LRB) over conventional construction, using a case study of identical conventional and isolated building constructed in the most seismically active region in India (Zone V). Base isolator is a device which decouples a super structure from its substructure resting on a shaking ground thus protecting structural and non-structural components. This project deals with design, modeling and analysis of G+6 rigid jointed plane symmetrical RCC frames for two cases. First case is fixed base and second case is base isolated (LRB). Building displacement and acceleration are compared for that both cases. For analysis ETABS software is used and for designing of isolator 1893:2002 (part 1) and Design of seismic isolated structures (F.Naeim and J.M. Kelly) is used by me. Keywords: Base isolation, lead-rubber bearing, response spectrum analysis, storey acceleration, floor displacement, storey drift, base shear. 1. INTRODUCTION Base isolation of structures is one of the most desired means to protect it against earthquake forces. The term base isolation have two word first is Ǯbaseǯ its meaning is a part that supports from underneath or perform as a foundation of a structure, and second is Ǯisolationǯ its meaning of the state of being disparate. The effective reduction of inter storey drift in the floor of base isolation system can ensure the lowest damage to facilities and also human safety. The concept of base isolation technique had been suggested in last few decades and the available technologies and the knowledge of base isolation system are getting mature and well established. Seismic isolation systems are more effective when applied to high stiffness, low-rise buildings, owing to their abilities to alter the characteristic of the building from rigid to flexible. An increasing number of structures to be isolated reflect the fact that base isolation system is gradually becoming accepted as a proven technology in earthquake hazard mitigation. Lead-plug bearings are made up of low-damping elastomers and lead cores with diameters between 15% to 33% of the bonded diameter of the bearing. Laminated-rubber bearings supplies the required displacements for seismic isolation.By combining laminated-rubber bearings with a lead-plug insert, which provides hysteretic energy dissipation, the damping required for a successful seismic isolation system can be incorporated in a single compact component.. The maximum shear strain range for lead- plug bearings varies as a function of manufacturer but is generally between 125% and 200%.. LRB isolators have cylindrical rubber bearings, which are reinforced with steel shims. Shims and rubber is placed as alternate layers. Steel plates are also provided at the two ends of the isolator. The steel shims boost the load carrying capacity, thus the structure is stiff under vertical loads and flexible under horizontal loads. Fig - 1: Lead rubber bearing The fundamental principal of base isolation system is to rectify the response of the structure so that the ground can move below the structure without transferring these motions into the superstructure. In an ideal system for the supple this separation would be total. But In the existing world there is a need to have some contact between the superstructure and sub structure. Fig -2: Behaviour of structure without and with isolator incorporation 1 Swapnil Ambasta, 2 Dushyant sahu, 3 G.P. Khare