May 1998

Takenaka Corporation

The Hankyu Five New Construction on which work is progressing in Umeda, Osaka, will open this fall as HEP FIVE. "HEP" is an abbreviation for Hankyu Entertainment Park, and it is striving to become a city-style shopping center integrated with HEP NAVIO, on which renewal work will commence in July this year.
HEP FIVE is a multifacility building incorporating shops and amusement facilities. It has a total floor area of 52,755 m², with three floors below ground and ten above ground. It also incorporates a Ferris wheel with a diameter of 75 m, a maximum capacity of 208 people (52 gondolas carrying 4 people each), and a height at the top of approximately 106 m.
The establishment of a Ferris wheel of this size inside a high-rise building is unprecedented.
In the past, Ferris wheels have been within the scope of construction for amusement manufacturers. In this case it had to be considered not only as an ordinary Ferris wheel, but also the mutual effects caused by its integration with the building had to be taken into account. So, in order to attain similar levels of earthquake resistance and wind resistance safety, Takenaka has been actively involved from the design stage.
Ferris wheels which stand on top of buildings are regarded as rooftop fixtures under the law, and as a result must be designed with the ability to withstand an earthquake force approximately three times that of Ferris wheels located on the ground. Due to the need to take into consideration the mutual effect between the Ferris wheel and the building in this case, earthquake response analysis was carried out utilizing a three-dimensional frame model integrating the Ferris wheel with the building, and the behavior of the building and the Ferris wheel were assessed appropriately to produce a safe design.
With regards to design of parts and connecting parts, the Building Standards Law has been applied to ensure safety against earthquakes, and in addition to this structural response we have fitted a vibration control device to each of the 52 gondolas to further improve the safety of passengers.

Photograph Showing Impression of Completed Building

• Development of Compact Vibration Control Devices for Gondolas
  Ferris wheel passengers range from infants to the elderly, so a vibration control device jointly developed by Takenaka, Tokkyo Kiki Co., Ltd, and Sanoyasu Hishino Akimasa Co., Ltd. was fitted to each gondola as a safety measure to ensure absolute safety.
  This vibration control device is of the passive type (note), and its mechanism is such that two additional weights called masses with a weight of 36 kg move when the gondola swings, and the movement of the masses is absorbed by a viscous fluid silicon oil damper, thereby reducing the swinging. In order to make the device more compact, the springs and the masses are integrated, and innovations have been made to enable masses to move greatly even with short springs.
  The dimensions of the vibration control device are 15 cm high, 27 cm wide and 107 cm long. Two devices are fitted above the ceiling of the gondolas, one on either side of the supporting axle.
  According to the damping effect obtained from simulation analysis, it is possible to halve the strength of swinging, and in the results of testing using a model of actual size it was possible to achieve the expected effect.

  Note: Methods of mechanically controlling vibrations of buildings can be broadly divided up into passive and active types. A passive control system reduces swinging by the inertia force of the damper, while an active control system detects swaying of the building, calculates the force required to stop the vibration using a computer, and actively reduces the sway.
  

  Testing the Gondola Actual Size Model

  Vibration Control System Fitted to the Ceiling of the Gondola (During Actual Size Testing)

  
  
• Other Modifications to Improve Passenger Safety and Comfort
  In order to provide passengers with higher levels of safety and comfort, it has been made impossible for the drive tires of the Ferris wheel to come away from the drive rail even in the event of a major earthquake, innovations have been made to enable the safe evacuation of passengers, and innovations have also been made to prevent the gondolas from swinging in high winds.
  The gondolas seat four passengers, and in addition to securing a comfortable space with an outer diameter of 2.25 m and width of 1.2 m, this is the first permanent Ferris wheel fitted with heating and cooling.
  A total of two air conditioners for cooling have been installed, one under each seat, while heaters have been incorporated into the seat and floor, thereby enabling heating and cooling.
  
  
• Overview of Construction

  Construction Site		3-1 Kakuda-machi, Kita-ku, Osaka City
  Clients		Hankyu Real Estate Co., Ltd., Hankyu Five Co., Ltd.
  Design		Takenaka Corporation
  Construction		Joint venture of Takenaka Corporation and two other companies
  Total Floor Area		52,755 m2
  Structure		S, RC, SRC/B3, F10, P1.
  Construction Schedule		June 1996 to November 1998

  
  
  
• Overview of Ferris Wheel

  Diameter		75 m
  Height		GL + 105.7 m (uppermost point)
  No. of Gondolas		52 (capacity 4 people)
  Total Weight		606.4 t (core axle weight: 56 t)
  Boarding Platform		7th floor
  Time Required for One Circuit		Approximately 15 minutes