Preparing for Mega-Quakes: Disaster Mitigation at the National Diet Library, Japan

Abstract

In Japan, efforts to improve earthquake resistance of buildings are continuing based on past experience and the assumption that another large-scale earthquake will occur in the near future.

The National Diet Library has implemented countermeasures for each of its five buildings depending on their age, location, functionality, and other conditions. The Brick Building of the International Library of Children’s Literature was the first library in Japan to be retrofitted with seismic isolation technology. This technique effectively lessens the shaking experienced by a building while preserving the building’s original architecture. On the other hand, conventional seismic reinforcement was implemented at the Main Building of the Tokyo Main Library, and there are three other buildings that have underground stacks, which is also an effective protection against earthquake damage. All three types of buildings survived the Great East Japan Earthquake in 2011 without any structural damage, but there were significant differences in the impact on the collections in the buildings. Aseismic isolation and underground stacks have provided better protection for collections. The NDL will continue its efforts to give proper consideration to both the risks we face and the constraints we work under in implementing measures to reduce damage and to effect prompt recovery from earthquakes.