"As my own individual research themes for long time, we have been
studying effects of seismic isolation and vibration control of buildings,
as well as indoor damage evaluation such as what kind of furniture falls
in what kind of vibration (during earthquakes), or how much it moves."
Dr. Mika Kaneko, General Manager of the Center for Safety and Reliability
Engineering, Institute of Technology, SHIMIZU CORPORATION was assigned
to Osaki Laboratory (at that time) when she joined the Company about 30
years ago, which had started in 1982 along with inauguration of Prof. Yorihiko
Osaki, former Professor Emeritus of Tokyo University, as Vice President
of the Company. There she was engaged in research using diverse simulation
analyses concerning earthquakes for nearly 20 years. Since then, she has
been devoting herself entirely to the research field. She looked back that
what she considered especially unique about these efforts was focus not
only on "whether a building itself collapses or not" in the earthquake
but also on the fact that "even though a building does not collapse,
its vibration causes very dangerous conditions, e.g. with furniture falling
down inside".
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Center for Safety and Reliability Engineering, Institute of Technology,
SHIMIZU CORPORATION |
Researches from such points of view were still kept on after she moved
to the Institute of Technology. 4 and half a year ago when the Center for
Safety and Reliability Engineering was established in the Institute, however,
she took a position as General Manager of the Center. Since then, she has
been engaged exclusively in management of research and development in the
Center she belongs to.
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Our user to feature in this issue is SHIMIZU CORPORATION, one of the socalled
super (major) general contractors that boasts of its history of more than
200 years for construction of buildings and civil engineering structures
with its abundant achievements. We put special focus on "Center for
Safety and Reliability Engineering", one of 6 Centers composing "Institute
of Technology" that takes charge of research and development and verification
of development technologies etc. towards realizing structures with high
added values.
Originally, the Company had introduced FORUM8 products since 1980's centering
on the design division. A year and a half ago, the Advanced Earthquake
Engineering Laboratory was established within the Institute of Technology.
At the same time, a large-stroke shaking table was built up and is operated.
It reproduces vibrations on the top floor of skyscrapers by reflecting
a variety of earthquakes using "UC-win/Road", FORUM8's threedimensional
(3D) real-time VR.
Aiming at Development of New Technology Required Based on a Hard Look at
What Things Will Be Like in 10 Years |
SHIMIZU CORPORATION was founded in 1804, 212 years ago when the founder
Kisuke Shimizu opened a business at the Kanda Kaji cho district of Edo.
Later, after constructing the West Wing of the Edo Castle, expanding into
Yokohama along with the opening of the port (1859), and learning construction
technology of western architecture there, it constructed a large number
of buildings and infrastructures that colored Japanese modern history in
and after the Meiji era. Through repeated expansion and restructuring of
the organization, it still puts an emphasis on diligent study of technologies
to lead the needs of the times in a wide range of areas of architectural
and civil engineering construction as well as provision of their outcomes.
In this process, Research and Development Section, predecessor of the Institute
of Technology, was established in the design department of the Company
in 1944. In 1972, the present Institute of Technology was constructed in
Koto-ku, Tokyo. In 2003, the new main building of Institute of Technology
was completed for the 200th anniversary of foundation.
Under the keyword "Prepare for the 10 years to come" (Mr. Hiroshi
Ishikawa, Director of Institute of Technology), the Institute takes an
approach of actively developing new technologies that will be required
in the future in anticipation of the times, says Dr. Kaneko, General Manager
of the Center.
The implementing entities of the Institute of Technology are currently
the following 6 centers. |
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Dr. Mika Kaneko, General Manager,
Center for Safety and Reliability
Engineering, Institute of Technology,
SHIMIZU CORPORATION |
- "Center for Construction Engineering" for technologies that forms
the basis in constructing buildings and civil engineering structures, including
materials, structural frames, soils and foundations, facilities, and fire
safety.
- "Center for Environmental Engineering" for environmental technologies
that are directly related with life, including wind and heat, acoustics,
nature, and healthcare.
- "Center for Safety and Reliability Engineering" that pursues
efforts to deliver safety and security to society through technologies
to forecast, evaluate, and minimize risks in the event of diverse natural
disasters such as earthquakes and accompanying tidal waves (tsunamis) or
abnormal weather.
- "Center for Energy Engineering" for technological challenges
concerning energy conservation in buildings and town blocks, adoption of
renewable energy, and atomic energy etc. while targeting a sustainable
low-carbon society.
- "Center for Social System Engineering" for software and hardware
technologies concerning new infrastructure construction that meets the
needs of societies, methods for preservation and renewal in consideration
of existing infrastructures and local values.
- "Center for Future Technology and Design" that seeks to create
inspirational spaces and environments as well as new value using advanced
technologies freely.
Their operations are supported by R&D Planning Department and R&D
Administration Center. Among 10,750 employees of the Company in total,
234 members including 181 researchers belong to the Institute of Technology.
The Center for Safety and Reliability Engineering has 35 staff members
including researchers (as of April 2016).
Positive Use of Advanced ICT for Earthquake Countermeasures etc. |
"Though 'Safety and reliability' covers a wide range of areas, it
is earthquake countermeasures that we are putting the greatest emphasis
(in our activities) on".
Dr. Kaneko, General Manager of the Center says that as stated before, the
Center for Safety and Reliability attaches great importance not only to
earthquake countermeasures but also to research and development with focus
on the risks caused by tsunami or abnormal weather such as torrential rainfall
and tornados in recent years.
Based on this, she classifies the approaches to these problems in the Center
into three types as follows:
- Evaluation technologies before disasters occur (software)
- Countermeasure technologies for particular targets such as earthquakes
(hardware)
- Preparation for the cases when disasters actually occur (skill)
As the specific results of these, he mentioned the following items.
- In terms of software, a system for proposing the optimum solution by predicting
and diagnosing vibrations of earthquakes and tsunami motions, and their
effects on buildings and facilities ("Shimizu's comprehensive disasterprevention
diagnostics system" and "Tsunami Simulation System" etc.)
- In terms of hardware, technologies and equipment for strengthening structures
directly (rotating inertial mass damper, partial base isolation system,
low-cost liquefaction countermeasure construction method, and seismicresisting
technology for ceilings)
- In terms of skills, systems for supporting the clients' safety and reliability
after the occurrence of earthquakes (a system for automatic judgment of
soundness of buildings right after the occurrence of an earthquake with
pre-installed sensors, and a system for allowing elevators to stop at the
nearest floor in conjunction with Earthquake Early Warnings).
The Company’s positive response to ICT (Information and communications
technology) also reflects on the basis of such development. For example,
in the system for automatically judging the soundness of buildings, a system
of IoT (Internet of Things), which attracts attention in recent years,
has been installed early ahead of others to install a large number of sensors
in the building beforehand.
Large-stroke Shaking Table Using UC-win/Road Installed in Advanced Earthquake
Engineering Laboratory |
"Since the old shaking table we used to have was made nearly 30 years
ago with motion (stroke) of ±20 cm, there was a limitation in reproducing
the vibrations (of the top floor of a skyscraper that may move more than
1 meter). So we started to think of creating a new shaking table before
the occurrence of the Great East Japan Earthquake (2011)".
It was encouraged to give shape to this idea when the Earthquake caused
large vibrations of super high-rise buildings in the city center of Tokyo,
which suddenly attracted attention, says Dr. Kaneko, General Manager of
the Center.
With this as the background, the Advanced Earthquake Engineering Laboratory
opened on the premises of the Institute of Technology in March 2015. It
was expected to serve as the basis for realizing "BCP (Business Continuity
Plan) of a rank up" by contributing not only to technological development
in terms of software and hardware but also to improvement in skills.
The facility as the centerpiece of the laboratory is a large-scale shaking
table "E-Beetle" and a large-stroke shaking table "E-Spider".
E-Beetle mounts the acceleration performance (Acceleration when loading
35 t: 2.7 G, stroke: ±80 cm) capable of reproducing vibrations of all kinds
of earthquakes in the world. Measuring 7 m square, the table (maximum weight
bearing capacity: 70 t) allows testing for constructing structures with
higher earthquake-resistance by loading a model of the building or a part
cut from the fullscale building on it to grasp the behavior of the building
up to its collapse and its seismic resistance performance.
On the other hand, E-Spider's maximum acceleration is 1 G (with 3 t load)
and amplitude is ±1.5 m. As it can be tilted diagonally in addition to
upwards and downwards motions, it allows reproduction of the vibration
peculiar to the top floor of a high-rise building. It makes it possible
to understand the behavior of furniture inside the rooms of the building.
Besides experiments of vibration, for the purpose of getting people to
feel bodily sensations of an earthquake by actually placing them on the
table, a cabin (a rectangle box) is mounted on the table measuring 4 m
x 4 m. The experiencing cabin is equipped with a large-scale screen on
the front, faced by the seats (for 4 people) and standing spaces (for 5
people). Enabled by UC-win/Road, it also incorporates a system for viewing
the video images and hearing the sound of falling furniture etc. within
the room according to the physics model in synchronism with the shaking.
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Earthquake simulation with UC-win/Road (left: offi ce, right: house).
Vibrations are reproduced by VR
to simulate their effects on the fi xtures and furniture inside the building. |
Utilization of E-Spider and Its New Possibilities |
In response to the specific request that they "want to create a shaking
table that gives visitors a vivid sense of earthquake motions by actually
getting on it, and see the video image (of inside of the room as it changes)
along with the shaking, the Company and FORUM8 held the first meeting in
April 2012. Later, the mechanism of synchronizing the images and sound
of VR with the shake on the side of the motion was built up while controlling
the wave pattern of the earthquake and calculating on a realtime basis
between E-Spider and UC-win/ Road. It is also possible to reproduce the
difference in vibration between a baseisolated building and a building
without base isolation, as well as the vibration of long-period earthquake
motion.
Since the operation started in the Advanced Earthquake Engineering Laboratory,
experiences of earthquakes with E-Spider have been made open to public
for the clients of the Company centering on the owners of buildings and
production facilities. It was so thriving as to involve a waiting list,
with 2,600 visitors in the last fiscal year (from April 2015 to March 2016).
Not a few people voiced their astonishment at its realistic shaking and
images, according to her.
It is also possible for Dr. Kaneko, General Manager of the Center to reproduce
the vibration of the concerned earthquake easily using the earthquake wave
pattern data made public by herself. Therefore, she pays attention to the
advantage that the in-house researchers can reflect the experiences on
their researches. She considers that it helps the research and development
to increase in speed.
Additionally, based on the data designed by the designer, it is possible
to have bodily experiences in advance as to how the building shakes, what
kind of effects are brought about on the building or inside the room by
different types of earthquakes that occur after the completion of the building,
while the building is still in the design stage. It is expected to add
persuasiveness to the explanation for their clients.
Moreover, it is also possible to apply E-Spider to research on the psychological
and physiological effects of seismic motions. Some papers have already
been issued on researches such as "Quantification of Human Senses
to Shake".
She is willing to use it effectively both in dealing with clients and research
& development.
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Introduction of the performances of E-Spider, a large-stroke shaking table
and how to use it |
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