EXPERIMENTAL STUDY ON MECHANICAL CHARACTERISTICS OF LARGE SCALE SLIDING SEISMIC ISOLATION BEARING OF TOKYO GATE BRIDGE

Abstract

 The large scale sliding seismic isolation bearing was employed on Tokyo Gate Bridge. The sliding isolation bearing consists of two supporting members: a horizontal buffer which resists horizontal reaction forces ; and a vertical bearing which bears vertical reaction forces and functions to attenuate energy via friction resistance of the sliding surface. Accordingly, a friction coefficient on the sliding surface is an important factor in designing the Bridge. In the past researches, it has been known that a friction coefficient varies depending on a surface pressure and speed of displacement. In this paper, we conducted a repeated loading test to study mechanical characteristics such as contact pressure dependence and velocity dependence of a friction coefficient in a sliding surface. We examined that, by calculating the dynamic response, how this factor affects the earthquake response of this bridge, and confirmed that the employed the large scale sliding bearing for seismic isolation reduces the movement of the bridge within the allowance range defined on the basis of the ground motion.