The earthquake that occurred on March 11, 2011 off the Pacific Coast of Tohoku
caused devastating damage to the northeast Pacific coast region of Japan.
We discuss the response to this earthquake of three buildings in Shimizu
Corporation’s Institute of Technology in Tokyo, each with a different type of seismic
isolation, and that of a test building for seismic isolation jointly built by
Shimizu Corporation and Tohoku University on the Sendai campus in Miyagi
prefecture, which was near the earthquake’s epicenter. The effects of seismic
isolation methods were verified through the observed earthquake responses of
the four buildings. In each of the three seismic isolated buildings at the
Institute, the observed accelerations on the floors were reduced to about half
compared to those on the ground. In the test seismic isolated building in Tohoku
University, the observed accelerations on the roof were reduced to about one
third compared to those in an adjacent conventional seismically designed
building.