In addition to general base isolation and vibration control technology, Takenaka Corporation has been developing related technologies to solve building-specific issues. We introduce two of those technologies here.

Swaying of upper floors = technology to control "whipping phenomenon"

Buildings that are comprised of a large low-rise section and an elongated high-rise section are prone to a "whipping phenomenon" in which the upper floors sway more during an earthquake.

Solved with “base isolation x centralized vibration control at a middle-story ”

In such buildings, a "whipping phenomenon" at the upper floors cannot be suppressed with a base isolation alone. However, this swaying can be controlled by installing centralized vibration control (vibration control damper) at a middle-story in addition to the base isolation .

As vibration dampers are concentrated at a middle floor, other floors can be maximized, and flow lines and views of office space are not obstructed.
In addition to minimizing damage to the interior and exterior of a building during a massive earthquake, the risk of furniture and equipment falling over is also reduced.

Example: New office building for Yomiuri TV

Technology that balances designability with the aseismic performance of an atrium roof that is attached to a base-isolated building

When a base isolation layer is installed at a middle floor of a building with an atrium, the atrium is generally below the base isolation layer.

In order to suppress swaying of the atrium roof during an earthquake, it was necessary to make the columns and roof members thicker, which led to a problem of poor appearance.

Solved with “atrium that straddles the middle floor base isolation x following column"

The roof is connected to the area above the base isolation layer by attaching ball joints to the upper and lower ends of the atrium columns. Through circular motion of the ball parts, it is possible for the columns to follow the roof, which will move slowly but significantly. This eliminates the need to make columns and roof members thick. In addition, it is possible to create a large atrium space irrespective of the level of the base isolation layer.

Example: Yokohama City Hall