OPTIMIZING THE DESIGN CHARACTERISTICS OF SEISMIC-ISOLATION DEVICE (LEAD RUBBER BEARING) FOR BRIDGES

Abstract

A seismic-isolation bridge must be effective for both medium sized earthquakes, which may be applied to the serviceability limit state design method, and extremely large earthquakes, which may be applied to the ultimate limit state design.
In this paper, the authors propose a practical design method that optimizes the characteristics of seismic-isolation device (Lead Rubber Bearing) for both types of earthquake. A design chart which can be applied to every bridge is offered. The domain of seismic-isolation characteristics that create a reasonable reduction of inertia force is then obtained.