Comments (0)

|

Comments This Article

Record Breaking Testing Tower by Mitsubishi

Solae Elevator Testing Tower (SETT), Inazawa – Japan

High rise structures have been an integral part of urban space in the recent past. There has been a constant research and development in the sustainability aspect of the buildings.  Experiments from architects with respect to design and aesthetic elements have added a new feather to the construction arena. Also, thanks to continuous innovation in the field of elevators that has led to the demand of these high rise structures. With these positive developments, we witness some of the awe-inspiring skyscrapers around the world creating their mark in the urban milieu. For any high rise buildings elevators constitutes an integral part hence, a lot of hrust is given to the efficiency of the elevators when used in such high rise buildings. It becomes imperative for an elevator manufacturer to assess its products, which is invariably done in a testing tower. With over 80 years of experience in providing reliable, high-quality products to both corporate clients and general consumers all over the world, Mitsubishi Electric Corporation took the plunge of erecting the Solae Elevator Testing Tower located at Mitsubishi Electric Corporation, Inazawa in Japan. According to Mitsubishi, the new precast-concrete-clad tower, called Solaé, is a direct response to a high-rise building boom. With record-breaking skyscrapers under construction in emerging markets like Dubai and Shanghai, the $50 million tower will be used to develop higher-speed, higher-capacity elevators. One such project has the goal of producing an elevator that travels faster than 3,300 feet per minute. The tower will also be used to test ropes and traction machines, prototype safety systems such as long-stroke buffers and large-scale safety gears, and technologies that lessen vibration and wind noise generated by high-speed elevator service.

At 173 meters height, it is the world’s highest elevator testing tower. Construction of the tower commenced in December, 2005 and completed in September, 2007. The tower is truly an architectural marvel of its kind. This highly acclaimed tower was completed within two years. Solae is being used to develop the technologies for ultra high-speed elevators in the 1200 m/min class as well as high-capacity elevators.  It will allow the company to further research and develop on the comfort of the ride, lower noise or vibration levels, safety and

other aspects of quality and reliability. Furthermore, it is planned for the tower to be used as a research facility for the cutting-edge technologies upon which future elevator concepts will be based.SETT Purpose

The Inazawa Works, Mitsubishi Electric's "mother" factory for its worldwide elevator business, not only manufactures 10,000 units of elevators and escalators annually, but develops the latest technologies for products in the global market as well. To assure the performance and quality of these elevators, the company previously had six testing towers to examine their products, including a 65 meter high tower that until now was the tallest at Inazawa Works.

With the recent increase of higher buildings in countries around the world, there has been an increasing demand for a more high-speed and high-capacity elevator. The new SOLAÉ testing tower will contribute to propel the development of elevators that fulfills such demands. Further, the tower, which can be seen not only from within the Inazawa city limits but also from neighboring areas and even aboard the Shinkansen bullet train, is expected to be endearing to local citizens and become a symbolic landmark of the community.

Attached Facilities

The showroom attached to SOLAE is designed chiefly for customers who are considering installations of elevators, escalators or building management systems. The building has three floors, with the showroom on the first and second floors and reception rooms on the third floor. The third floor is also connected to the testing tower.

The new showroom on the first and second floors includes the following:

•  On the first floor, there are four zones: an area introducing Inazawa Works, a historical zone with the restored first elevator of Mitsubishi Electric as well as photographs of other memorial elevators, a zone with an interactive exhibit of various kinds of elevators and its latest technologies, and an area introducing our escalators.
• The second floor has three zones: a section using actual elevator parts to select one’s own design for cars, ceilings and other parts in the elevator, a zone introducing the maintenance services of Mitsubishi Electric, and a zone with an interactive exhibit of the company's security related products.

Wind effect

In the Solae Elevator Testing Tower project, the influence of wind becomes extremely large because the building is of light weight and slender shape having only elevator shaft. Explaining about the challenges encountered during the execution of this project Konosuke Masuda, Manager, General Affairs, Inazawa Works, Mitsubishi Electric Corporation says, jnm Thus, for the preliminary wind tunnel experiment, the planar shapes were circular and square, and in addition, for the square, wind tunnel experiments were conducted on models of three cases depending on presence/absence of cut-out on four corners.

As a result of the wind tunnel experiments, the following structural design policies were determined.

• The planar shape should be of square plane hardly generating vortex-induced vibration at low wind velocity.
• Cut-out should be provided and be approximately 1/10 of building plane.
• It is necessary that the targeted building own natural period be a quite short period in comparison with height of the building, and it should be brace structure.
• Oil damper additive damping should be taken into consideration in addition to damping of building to reduce response.

Key Performance

One of the key indicators of an elevator's performance is speed. Mitsubishi is already setting the world standard in this area with a determination to achieve even better performance. Mitsubishi's current goal is to develop the world’s fastest elevator, a system capable of speeds in excess of 1,000 meters per minute.

The pursuit of speed is also the pursuit of safety, especially in relation to acceleration, deceleration and emergency stopping. We also need to develop advanced systems to control noise and vibration, which tend to intensify as the speed increases. These aspects cannot be verified solely through simulations.

SOLAÉ will allow us to conduct tests in an environment that closely resembles actual conditions of use, and its completion represents a major step forward in Mitsubishi’s effort to create the world’s fastest elevator.

Accepting the fact that the Speed is not only priority, end users increasing diverse range of features, including space-saving designs, barrier-free access, as well as reduced energy consumption and other improvements in environmental performance, are also kept in mind.

Economical design Optimisation in design was achieved by employment of hybrid structure of iron frame structure and reinforced concrete structure. The whole design concept is based on three aspects. Hybrid Structure- It is most economical to design tower building so that design external forces of wind load and seismic load are nearly equal. As structural type, iron frame structure tends to be dominantly subject to wind load and reinforced concrete structure tends to be dominantly subject to seismic load. This building is designed such that wind load and seismic load are nearly equal by setting the lower-rise section up to 40 m to reinforced concrete structure and stable shape increasing rigidity and building weight, and setting the higher-rise section to highly rigid iron frame structure of three layers constituting X-shape brace.

Planar shape reducing wind load - According to consideration of results of the preliminary wind tunnel experiments, a shape in which planar shape is square and cut-outs are provided on four corners of the building is most effective to reduce wind load. This building is designed to be of a square of plane 17 m ´ 17 m and of a shape in which cut-outs of 1.8 m (approximately 10 percent of building width) are provided.

Varying configuration in lower-rise section - The lower-rise section of the building is provided with a structural frame of 20 m ´ 20 m rotated by 45° to increase rigidity and torsional rigidity of the building. To change this planar shape of higher-rise section and lower-rise section is also effective to reduce wind load by disturbing vortex which is generated when wind is applied to the building.

Cutting Edge Technology

When asked Konosuke Masuda about the cutting edge technology adopted in reducing the overall cost of construction of the project, he says, "For the purpose to reduce wind load, the structural frame is provided with an oil damper to increase damping force. In addition, the oil damper certainly also ensures stable performance for long continuous time vibration such as typhoon. "He further adds, "In order to control vibration at time of strong wind by seasonal wind, an active controlled vibration control device hybrid mass damper (HMD) is placed on the top floor of the building to ensure dwelling character and make a plan so as to cause no trouble on the test of the fast elevator. The damping constant when switching the vibration control device from vibration to vibration control state is approximately 11.7 percent  and then it is judged that dwelling character is ensured even at time of strong wind by seasonal wind and there's no influence on the test of the elevator."

For external finish, tile hammering PC plates are used, and dirt adhered on surface of tile is hardly adhered due to self-cleaning action by photo catalysis technology. In addition, joints of PC plates are not provided with locations of stop in the way and are planned to securely carry rain water with dirt to the lower end.

Sustainability Criteria

Many eco-friendly products have been used in the construction of this state-of-the-art tower. Electric furnace steels are used for some of the building frames in iron frames. Electric furnace steels are made by recycling irons. Recycling irons also contributes to energy saving. In steel making process with electric furnace, consuming energy per ton of crude steel can be saved because there's no pig iron manufacturing process. This allows CO₂ emission causing global warming to be reduced, therefore, electric furnace steels are said to be earth-friendly eco-material.

As for the environmentally-benign features, photocatalytic tiles on the outer walls are adopted in order to resist and decompose dirt and even bacteria. It is thought that this feature will reduce the use of cleaner.

Apart from being the world's tallest test tower, SOLAE is also important for other reasons. SOLAÉ is also a symbol of Mitsubishi Electric's continuing commitment to improvement and quality and our passion for the creation of superior products.

I believe that "the presence of SOLAÉ is a source of motivation for all employees. We also wanted SOLAÉ to become a popular landmark for the people of Inazawa City in Aichi Prefecture, where the Inazawa Works is located. We took special care of the design, and at night we illuminate the tower. Even the height was selected to emphasize the local link. In the Japanese punning language used to create telephone number mnemonics, the number "173" sounds like "Inazaw".

Combating Seismic and Wind Forces

The bevelled edges called chamfered corners effectively change the wind directions around the tower and curb the impact of wind to mitigate the tower's variable vibrations. Oil damper and an anti-vibration system prevent the tower from vibrating due to wind as well.

Future Developments

Konosuke Masuda, Manager, General Affairs, Inazawa Works, Mitsubishi Electric Corporation

Mitsubishi Electric will further accelerate R&D on safety, reliability, and ride comfort, as well as expand the company's elevator business through development of cutting-edge products, such as the world’s fastest elevator that travels at more than 1000 meters per minute, as well as high-capacity elevators that can carry a large number of people at once. Specifically, work will progress on developments in the following areas:

Large-size traction machines and parallel-driving power systems for high-speed/high-capacity elevators Safety systems, including long-stroke buffers and large-size safety gears Durability and performance of ropes and traction machines Technologies to lessen vibration/wind noise generated when elevators travel at high speeds The tower will enhance the company’s accumulation of cutting-edge technologies and product development capabilities, with an aim to accomplish future concepts for the elevators.

Concluding his remarks on the aesthetic element of the structure, Konosuke Masuda says, "The concept and the design of the tower symbolises the company's growth taking root in ground and extending higher in the sky in clear shape. It expresses verticality of test building with straight lines and showroom with gentle curves."

EOM

Facts and Figures

• Location: Mitsubishi Electric Corporation Inazawa Works (1 Hishi- machi, Inazawa City, Aichi Prefecture, Japan)
• Height: 173.0 m (568 feet)
• Number of Floors: Equivalent to 40 floors of a building
• Area of Construction: 440 square meters
• Construction Time: December 26, 2005 to 26^th September, 2007
• Attached Facilities: Showroom and other testing facilities
• Total Investment: 5 billion yen (including related facilities)

Features of the New SOLAE Testing Tower

• World's highest elevator testing tower as of December 20, 2007, at 173.0 meters in height
• Unique design: the lower part of the tower with a twist of 45 degrees
• Illuminated at night
• Stable testing environment made possible by oil dampers and an anti-vibration system that prevents the  tower from vibrating due to wind

 State-of-the- Art Facilities

   Main Features of Structure

• Economical design by employment of hybrid structure of S structure and SRC structure
• Planar shape reducing wind load
• Lower-rise shape rotated by 45° from higher-rise
• Addition of damping force using oil damper
• Active damping which allows for damping and vibration

     Main Features of Electric Facilities

• Light-up on top allowing for multicolour expression by LED
• Very narrow angle light-up on four corners employing xenon light source
• Measures for side lightning protection
• Counter measure for radio wave reflection on tiling PC in which ferrite is embedded

    Main features of mechanical facilities

• The biggest feature is a system of void ventilation applying building frame heat storage.
• Because half of the building inside is elevator shaft, it was a concern that temperature on the higher-rise section of the building rises due to chimney effect by solar radiation heat, causing trouble on tests.
• Void ventilation was proposed for the purpose to actively take cooled outside air in the night in the building to stop day time ventilation in which temperature rises and alleviate rise in temperature in building by building frame heat storage.