Title: Seismic Rehabilitation of Existing Reinforced Concrete Structures Using Base Isolation Systems

Author(s): Himat Solanki

Publication: Symposium Paper

Volume: 160

Issue:

Appears on pages(s): 255-274

Keywords: base isolation; bearings; buildings; earthquake-resistant structures; reinforced concrete; renovating; Structural Research

DOI: 10.14359/1459

Date: 6/1/1996

Abstract:
Various techniques are available for the seismic rehabilitation of existing structures, such as adding cross bracings, structural/shear walls, base isolation systems, etc. The cross bracings and structural/shear wall help reduce the drift and increase the ductility of the structures. The base isolation systems reduce the effect of the peak ground acceleration and, hence, the drift. In this paper, the base isolation systems have been considered to rehabilitate the existing reinforced concrete frame structures. Review of various base isolation systems used in reinforced concrete structures for seismic response is evaluated. An analytical procedure is described for a frame building supported on isolation bearings. The study is based on a single degree of freedom (SDOF) with appropriate hysteretic properties. Different geometries, variation of bearing stiffness, and ground motion are considered. Inelastic behavior by increasing the effective natural period of vibration and the damping ratio of frame is considered. The viscous damping coefficient and hysteretic damping ratio for isolation bearing were considered from the shear load deflection relationship of isolation bearings. The proposed procedure is applied to evaluated the Uniform Building Code (UBC) requirements of reinforced concrete frame buildings.