The 40th-Year Seismic-Isolation Demonstration Experiment PR Presentation was held at OKUMURA CORPORATION’s Technical Research Institute in Tsukuba, Ibaraki Prefecture, commemorating the 40th anniversary of the completion of Japan’s first practical seismic-isolated building. A demonstration of the free-vibration experiment and a tour of the research institute were made public, with a focus on the continued verification and wider adoption of seismic-isolation technology.
On 28 October 2026, the 40th-Year Seismic-Isolation Demonstration Experiment PR Presentation was held at OKUMURA CORPORATION’s Technical Research Institute in Tsukuba, Ibaraki Prefecture. President and Representative Director Okumura Takaten (奥村太加典), Technical Research Institute Director Ue Hiroki (上寛樹), and guest Aoi Morikawa (森川葵) attended. The event provided an opportunity to look back on the building’s history as Japan’s first practical seismic-isolated building and on the development and wider adoption of seismic-isolation technology.
An overview of the free-vibration experiment was presented. The administration building is a seismic-isolated structure completed in 1986, and the test method involved using hydraulic jacks to push the building 10 cm and then release it to verify the performance of the seismic-isolation devices. The 10 cm displacement was described as equivalent to a seismic intensity of lower 6, and data from the past 40 years indicated that the stiffness change rate was expected to have risen by approximately 12%.
Equipment at the test site, including the reaction wall area, seismic-isolation pit and long-period ground-motion simulator, was introduced. The institute also opened its top-level domestic testing environment, including a three-dimensional shaking table and a long-period shaking table. Demonstrations of low-cost, new earthquake countermeasures, including reproductions of waveforms from the Kumamoto and southern Hyogo Prefecture earthquakes, were also presented.
Aoi Morikawa (森川葵) appeared wearing a new uniform and described her impressions after experiencing the power of the experiment and the significance of seismic-isolation technology. A talk show followed, along with a public interview with technical staff. Finally, the future prospects for seismic-isolation technology were discussed, including stronger advance disaster prevention and faster recovery after disasters.