International Journal of Engineering Research

Pravin Jagtap ¹, Niranjan Muley ², Vasant Matsagar ¹

Affiliations
1 Indian Institute of Technology (IIT) Delhi, Hauz Khas, 110 016, New Delhi, IN
2 Government College of Engineering Aurangabad, New Osmanpura, 431 005, Aurangabad, IN

Abstract

In this paper, investigations are reported for the seismic response of the secondary systems (SS) housed on the floors of the fixed-base (FB) and base-isolated (BI)primary structures (PS). Various SS serves as life line systems in civil structures such as nuclear power plants,aerospace industries, hospitals and several important publicutility buildings/structures. After the earthquake events proper functioning of these SS is always anticipated to avoid social and economic chaos. The primary structure considered in the current study is a real-life reinforced cement concrete (RCC) framed structure. The structure is isolated with a combination of lead rubber and sliding type of isolation devices. Numerical model of the RCC framed structure with and without base-isolation devices is developed and study is performed by attaching the SS at different floor levels of both the fixed-base and base-isolated structures under the excitation of seismic loadings. It is observed that in case of the base-isolated structure seismic performance of SS is enhanced and it is concluded that in the base-isolated structure, acceleration response and thereby seismic design forces acting on the SS reduces in comparison with fixed-base conditions of PS. Comparative assessment for performance of the SS housed in a fixed-base and base-isolated PS is carried out through the parametric numerical investigations for various dynamic properties of the SS. The information obtained from the parametric studies gives an idea for design of the SS in considered range of the dynamic properties of the SS.

Keywords

Base Isolation, Earthquake, Primary Structure, Secondary System.

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