Design and analysis of base isolated structures

Abstract

Development in the design of earthquake resistant buildings has been growing since about 100 years ago. In the design of earthquake resistant buildings, the main aspects to consider are life safety and damage reduction on architectural element caused by the earthquake. However, with the development of age, modern buildings contain sensitive and expensive equipment that become vital for business, commercial, education and healthcare. Hence, the equipment inside the building needs to be protected when the earthquake occurs. The basic principle of a base isolation system is to provide flexibility in the building and at the same time provide damping to prevent amplification caused by the earthquake. By placing structure on the base isolation system, it will prevent horizontal movement of the ground transferred to the structure and produce a significant reduction in the acceleration of the earthquake. This paper explains about the design and analysis of a base isolated structure. The base isolation system used is Lead Rubber Bearings, High Damping Rubber Bearings, and a combination of those two bearings on a 20-story building. The main focus of this paper is the comparison of the response between a fixed base structure and the base isolated structure and the comparison of the response generated by each type of base isolation system. The compared responses are the natural vibration period, the base shear, and the base isolation hysteretic curve. The design procedure used is based on SNI 1726-2012. The conclusion of this paper is the effectiveness of a base isolated structure is based on the generated response. © 2013 WIT Press.