Development of Three-dimensional Seismic Isolation System using Air Levitation, Negative Stiffness Link and Air Dumper

Abstract

After the Great East Japan Earthquake of 2011 and the Kumamoto Great Earthquake of 2016, it seems necessary to upgrade earthquake countermeasure technology for further infrastructure conservation. As one of these efforts, we began developing a high-performance three-dimensional seismic isolation system that can isolate vibration to a level that people can not feel. This paper describes the full-scale seismic excitation experiments on new three-dimensional seismic isolation device using a pneumatic cylinder and the negative stiffness linkage in parallel on the air flotation stage. As a result of the excitation experiment of the seismic waves of KiK - net Mashiki-Machi (the Kumamoto Earthquake), the acceleration of the seismic isolation system was reduced to 1/15 in the horizontal direction and 1/3 in the vertical direction.