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With a high predicted probability of a 70% chance of a major earthquake occurring within the next 30 years, including a Nankai Trough earthquake and an earthquake directly beneath the capital, Disaster Prevention Day is being celebrated in the COVID-19 era. I think many people have reaffirmed the importance of "everyday preparation" through their experience with the new coronavirus.

This time, we bring you the story of the team that developed a series of disaster-resistant building materials to protect workplaces.

Uchida

As we are the only company in the industry that has a vibration testing laboratory, we are in an environment where it is easy to carry out vibration tests simulating major earthquakes. We carefully check the earthquake quality of the products we develop every day, but after the Great East Japan Earthquake, we felt a strong need for partitions that can withstand earthquakes that exceed "assumed" levels, and so we began developing a series of disaster-reducing building materials.

First, we developed the "High Earthquake Resistant Partition G" that can withstand a major earthquake of magnitude 7, followed by the "Seismic Control Partition X" that prevents ceilings from collapsing. After that, as we are a comprehensive office manufacturer, we wanted to go beyond the framework of partitions and apply our know-how to storage units, which are the most vulnerable to damage during earthquakes, and so we took on the challenge of commercializing the "L-FORCE" fall prevention unit. All of these disaster mitigation building material series are the product of our members' tireless pursuit of disaster mitigation, and we are proud of them.

Matsuyama

I was in charge of developing the "High Earthquake Resistant Partition G," which was the first in our disaster mitigation building materials series. I still vividly remember the shock I felt when I received a report that the partitions inside buildings had collapsed immediately after the Great East Japan Earthquake.

As Uchida mentioned, we felt a strong need to develop a product that could withstand even "unforeseen" earthquakes, so we started from scratch in terms of design rather than just extending what had been done up until now, and thoroughly reviewed everything from the design of a new mechanism to absorb the shaking of a major earthquake to the length of the hooks that hold the panels.

Furthermore, in terms of quality, we had many discussions with a certain design firm we were working with at the time about what standards we should meet. We set an extremely strict standard of a story displacement of 1/40*, which is unavoidable in order to withstand future major earthquakes. We then conducted numerous vibration tests and successfully brought the product to market.

When the product was commercialized, I was simply happy to have created something, but my desire to see it become more widely used and ensure the safety and security of as many workers as possible was stronger.

I am no longer in charge of the disaster mitigation building materials series and am now mainly in charge of developing new glass partitions, but my attitude toward facing earthquakes has remained unchanged since that experience.

*The normal floor displacement standard for partitions is 1/100.

Kawai

I was in charge of developing the second product, "Seismic Partition X." This product is for customers who live in old buildings (conventional suspended ceilings). The earthquake resistance of buildings themselves has made great strides, and with the progress of large-scale redevelopment in the metropolitan area, the number of safe buildings is increasing. In order to keep up with this, Matsuyama developed "High Earthquake Resistant Partition G" with the idea that it is also necessary to make non-structural components earthquake-resistant. However, we also received many voices from customers who are not living in such buildings and are concerned about earthquake resistance measures.

The conventional suspended ceilings that are often used in old buildings are prone to shaking during earthquakes, and they do not have sufficient seismic reinforcement, making them at high risk of collapsing in the event of a major earthquake.

We wondered if we could address this issue with a partition that can be erected under the ceiling, and developed the Seismic Partition X. By incorporating braces and dampers inside the partition, we succeeded in creating a unique technology that reduces the risk of ceiling collapse. We also conducted a structural analysis of this product with Structural Planning Institute, and were able to confirm that it performs well over a wide range. We believe that by increasing the number of "options" in our disaster mitigation building materials series and making it suitable for any situation, we have been able to offer a wider range of proposals.

Tanaka

I worked with Kawai on the development of the third product, "L-FORCE," which prevents storage units from tipping over. I had just joined the company at the time and was assigned to the partition design department, so I never dreamed that I would be involved in the design of storage units.

All of our disaster-reducing building materials series have industry-leading earthquake resistance, but in order to fully utilize that performance, we had the problem of not being able to fasten the storage unit to a wall.In addition, the Tokyo Fire Department guidelines and other sources suggest that fastening the storage unit to a partition with an L-shaped fastening bracket poses the risk of it getting caught in the ceiling or wall and collapsing, so we began developing a fall prevention measure to avoid the issues with our products and the dangers of current measures.

"L-FORCE," which was commercialized based on this background, does not require any fastening to the floor; it only requires six screws to be fastened to the baseboard at the bottom of the wall, and the product has cleared the quality target of not allowing the storage unit to tip over even if there are two consecutive major earthquakes of magnitude 7, which was set based on the lessons learned from the Kumamoto earthquake.

I was inspired by their attitude of not being limited by the framework of partitions, but instead working on anything that contributes to a safe and secure office space. Now I am challenging myself to develop new products that are just as good as my predecessors.

ITOKI has been thinking about how to create an "earthquake-resistant" space in preparation for a major earthquake that may occur again in the near future. The answer they arrived at is the idea of "disaster reduction," which involves identifying key points and firmly protecting those places.

ITOKI will continue to lead the way as a pioneer in disaster mitigation.

High Earthquake Resistant Partition G" product page: https://www.itoki.jp/products/zoning/partition_g/
"L-FORCE" product page: https://www.itoki.jp/products/zoning/l-force/