Seismic Isolation Floor (Shimizu ANSHIN FLOOR)

The Seismic Isolation Floor is a low-cost seismic isolation system for operating rooms that only takes a short time to build. It is highly effective at isolating the room from seismic vibration.

This seismic isolation system is simply constructed by using just two thin steel plates. The upper flat plate slides on the embossed plate during an earthquake. At just under 5 mm thick, it can be adapted to both renovation and new construction. The cost is only half to two-thirds of the cost of a regular seismic isolation floor system, and it takes about half as long to install.

Shimizu constructed Tochigi Medical Center Shimotsuga and installed the system in the operating rooms for the first time.

The Dynamic Screw^*1 is a rotating inertial mass damper that efficiently reduces shaking during a large earthquake by converting the seismic force into energy that rotates the flywheel. The rotation of the flywheel manifests damping ability equivalent to 4,000 times or more than the actual mass. The combination using the flywheel enables shortening of the subsequent shaking time.

In a massive earthquake in the Nankai Trough, which has a high probability of occurring, the ultra-high-rise buildings in the Tokyo metropolitan area and other major cities could experience long-period ground motion that cause the buildings to slowly sway by a large amount over a long period of time. This device protects ultra-high-rise buildings from such long-period ground motion.

1 Jointly developed with Kayaba System Machinery Co., Ltd., NSK LTD., and Heiwa Hatsujyo Industry Co., Ltd.