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Takenaka Develops the “Takenaka Base Isolation Monitoring System” to Continuously Remotely Monitor Deformation of Base Isolation Devices

—Beginning of aggressive efforts to improve the precision of the execution of base isolation work—

November 29, 2011Takenaka Corporation

Takenaka Corporation (President: Toichi Takenaka) has developed the “Takenaka Base Isolation Monitoring System” (patent pending) to continuously remotely monitor deformation of base isolation devices and the temperature inside the base isolation layer during the construction of a base-isolated building.The company and has installed the new system for the first time in the Shonan Research Center of Takeda Pharmaceutical Company completed in February 2011.
This research center is a large-scale base-isolated building, so to ensure that the base isolation devices will function effectively during earthquakes, Takenaka had to perform real-time monitoring of the impact of the drying contraction, thermal distortion and loads of the building body during its construction on the deformation of the base isolation devices.
This system was developed and introduced during the construction of this research institute in order that Takenaka Corporation, the industry leader in base isolation work, can further improve the precision of its construction work.
The number of base-isolated buildings in Japan has been rising in recent years, and it is predicted that their construction will continue to increase as a reaction to the Great East Japan Earthquake of March 11, 2011. Takenaka Corporation will work hard to popularize this system, in order that it can perform even more precise construction work in a variety of construction environments when installing base isolation devices in large level buildings, installing intermediate floor base isolation, or retrofitting base isolation devices.

Outline of the new system

The “Takenaka Base Isolation Monitoring System” automatically measures horizontal deformation and vertical height of base isolation devices and the temperature of the base isolation layer once every hour using measurement sensors.
Multiple measurement data about the inside of the base isolation layer is collected and simultaneously transmitted by wireless to a PC in a remote office.
Specialized software displays graphs and lists on the PC screen, allowing operators to sequentially check the data.
When measured data has exceeded a control value, an alarm display appears on the screen. The radio communication technology applied is “Hitachi AirSense II” from the Hitachi Corporation.

<System image>

Normally, the execution of base isolation work is managed by inspectors entering the base isolation layer and using measuring instruments to measure deformation of the base isolation devices two or three times during execution, but measurement work in a base isolation layer which is not easily accessible is an extremely labor-intensive task. When measurements are performed this way, it is difficult to perform timely and high precision quality control and to clarify the degree of impact that various factors occurring during execution have on deformation of base isolation devices.
The “Takenaka Base Isolation Monitoring System” achieves high precision real-time management from a remote location using wireless communication technology as it reduces measurement labor and cost requirements. Also, by accumulating device deformation and temperature data continuously during construction, it permits quantitative analysis of the impact on the deformation of the devices of loads and temperature fluctuations occurring during construction.

Beneficial features of the new system

  • It is a system which measures the day-to-day fluctuation of the deformation of base isolation devices.
  • It can continually perform frequent (can be set appropriately at about once/hour) automatic measurements of deformation of base isolation devices and the temperature of the base isolation layer.
  • It can be used to check data in real time on a PC installed at a remote location, and the accumulated continuous data can be used to clarify the impacts of a variety of factors (temperature fluctuation, load during construction).
  • It can be operated not only during construction of the base isolated building, but as a maintenance tool after it has been completed.
  • It can be introduced and operated at low cost by simplifying the installation of the rubber bearings and other base isolation devices.
  • System measurement sensor installation hardware that will not obstruct horizontal deformation of the base isolation devices during earthquakes was simultaneously developed.

Outline of the Shonan Research Center of Takeda Pharmaceutical Company

  • <Photo showing the outside of the building>

  • <View of the system when installed>

Building name Takeda Pharmaceutical Company Shonan Research Center
Client Takeda Pharmaceutical Company Limited
Location 2-26-1 Muraokahigashi, Fujisawa City, Kanagawa Prefecture
Construction manager YAMASHITA SEKKEI INC., Yamashita PM Consultants Ltd.
Basic design/Construction supervision PLANTEC ARCHITECTS INC.
Detail design Takenaka Corporation and others
Construction Takenaka Corporation
Structure Steel, Base-isolated structure
Number of floors 10 fl. aboveground (research wings)
Building area 72,323 m² (including attached wings)
Total floor space 310,474m²(including attached wings)
Work period June 2009 to February 2011