Effect of lead-rubber bearing isolators in reducing seismic damage for a high-rise building in comparison with normal shear wall system

Abstract

Seismic earthquakes are a real danger for the construction evolution of high rise buildings. The rate of earthquakes around the world is noteworthy in a wide range of construction areas. In this study, we present the dynamic behavior of a high-rise RC building with dynamic isolators (lead-rubber-bearing), in comparison with a traditional shear wall system of the same building. Seismic isolation has been introduced in building construction to increase the structural stability and to protect the non-structural components against the damaging effects of an earthquake. In order to clarify the influence of incorporating lead rubber bearing isolators in the seismic response and in reducing seismic damages; a comparative study is performed between a fixed base system (shear wall system) and an isolated base system (Lead Rubber Bearing) on an irregular high rise reinforced concrete (RC) building located in Beirut consisting of 48 storeys almost asymmetric orthogonally. For this purpose, a non-linear analysis of a real earthquake acceleration record (EI Centro seismic signal) is conducted, so that the mode shapes, the damping ratio and the natural frequencies of the two models are obtained using ETABS software. The results prove a substantial elongation of the building period, as well as a reduction in the building displacement, the roof acceleration, the inter-storey drift ratio and the base shear force of isolated building relative to fixed-base building. This study proves that this technology is applicable to high rise buildings with acceptable results.