Soft-Landing Base-Isolation System

Abstract

The authors are developing a new retrofitting method for low seismic performance buildings, especially for soft-first-story buildings. The concept of the method is that the new column, which has the base-isolation system at its middle height, is attached to the existing column by the compression force with PC bars. The existing column will fail in shear during an earthquake, and then the building becomes to be base-isolated. One of the big advantages of this method is that the retrofitting cost can be low compared to the conventional base-isolation retrofitting technique, since the existing columns do not have to be cut prior to an earthquake, which costs a lot. The paper will present the outline of the system and the results of experimental tests which includes shaking table test and static loading tests.