Open experiments of technologies for sediment removal from dam reservoirs
 Conceptual image of sheet and suction pipe sediment removal technology |
 Photograph of the plane figure appearing in the lower right of the “Conceptual image of sheet and suction pipe sediment removal technology” Sediment is being suctioned out. |
 A view of the air valve sediment removal facility experiment |
When a dam is built on a river, sediment that flows with the river accumulate in the dam reservoir. This leads to the following problems:
- Reduction in the effective capacity of reservoir
(Although many dams in Japan have capacities that take into account sediment accumulation over 100 years, there are reservoirs in which sediment is accumulating with unanticipated speed.)
- Changes in downstream riverbed environments
(For example, decreased amount of small-grain sediment in riverbeds, non-replenishment of riverbed material, etc.)
- Decrease in sandy beaches on downstream coasts
Dealing with these problems requires sediment removal technologies that
supply accumulated reservoir sediment to downstream river areas in order
to extend the life of the reservoir and improve downstream riverbed environments.
The River and Dam Hydraulic Engineering Research Team is engaged in research
on sediment removal technologies to address this need. For two technologies
that we jointly developed with private companies, we used model experiments
to successfully confirm that it is possible to remove sand using the differential
water head energy between upstream and downstream of the dam. On Dec. 20th,
2007, we conducted sediment removal experiments for these technologies
that were opened to the public.
On this day, we gave a brief explanation of sediment removal technologies before presenting the following three experiments at the Dam Hydraulic Laboratory located in the PWRI:
- Sheet and suction pipe sediment removal facility experiment
- Air valve sediment removal facility experiment
- Dam hydraulic model experiment
Three media organizations; seven organizations affiliated with the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and local governments; and a total of 21 private companies (including civil engineering consultants, construction companies, and manufacturers) participated in the open experiments. A question-and-answer session was also held that sparked active discussion of the onsite applicability of sediment removal technologies and the schedule for future onsite demonstrations among other topics.
Although we are still testing the abovementioned technologies in laboratory
models using non-cohesive sand, we intend to continue our R&D toward
their practical application in the future.
(Contact: River and Dam Hydraulic Engineering Research Team)
Report on the “Planning and Design of Water Cycles”seminar
 Keynote lecture by Professor Emeritus Asano of the University of California |
 How treated wastewater is used in California |
 Panel discussion |
On Jan. 16th, a Planning and Design of Water Cycles seminar was held in
Osaka. These days, considerable attention is being paid to increasing instability
of water resources due to the effects of global warming and to loss of
waterfront areas in major cities. Thus, planning and design of water cycles
are expected to contribute to sewerage systems that create new water resources
through wastewater reclamation. This seminar featured lectures and a panel
discussion to deepen understanding of the current situation and issues—both
in Japan and abroad—that concern wastewater reclamation and water
cycles and, further, to consider sewerage systems of the future.
Leading off the seminar was a keynote lecture by Dr. Takashi Asano, Professor
Emeritus of the University of California and recipient of the Stockholm
Water Prize, which is called the “Nobel Prize of water.” Dr.
Asano, who was visiting Japan as a PWRI fellow, spoke on the need for use
of reclaimed wastewater in the State of California, USA, as well as the
current situation and relevant issues concerning such use.
In Los Angeles and San Diego—both large cities located in southern
California’s arid region—it is expected that water demand will
increase in line with continually growing populations. On the other hand,
because means for obtaining new water supplies are limited, reclaimed wastewater
is attracting attention as a sustainable water resource. Reclaimed wastewater
is already being used as water for agriculture, landscape irrigation, and
industry. However, there are now projects underway that seek to go further
by reclaiming wastewater with more advanced technologies (reverse osmosis
membranes, etc.) and letting it seep underground so that it can be used
as drinking water. Dr. Asano noted that communication will be important
here to gain the understanding and support of residents.
The seminar also presented a panel discussion and other opportunities for
debate among university professors. Topics included methods for appropriately
managing water resources, methods for ensuring the safety of reclaimed
wastewater, the importance of sanitation facilities to protect the health
of people in developing countries, and the need for Japanese companies
to build frameworks for entering the world water business.
Some 270 people participated in the seminar and listened intently to the lectures. Their attendance undoubtedly gave them hints for considering the roles that sewerage systems should play in the future.
(Contact: Water Quality Research Team)
Conclusion of a “memorandum for collaboration and cooperation in civil-engineering technology” with Kumamoto City
 Signing of the memorandum by Mayor Kohyama and PWRI Chief Executive Sakamoto |
 Conclusion of the ”memorandum for collaboration and cooperation in civil-engineering technology” |
 Information exchange with technical personnel of Kumamoto City |
On Jan. 16th, 2008, PWRI signed a memorandum with Kumamoto City for the purposes of mutual collaboration and cooperation and contribution to efficient development and management of high-quality infrastructures. The signing took place at Kumamoto City Hall.
Kumamoto City seeks to become a “government-designated city”
in the near future, and is moving forward with efforts to develop its urban
infrastructure and revitalize its city center in anticipation of full-scale
opening of the Kyushu Shinkansen's Kagoshima route. As it does so, the city
has a keen interest in approaches to new civil-engineering technology.
Having a solid understanding of such technology, the city showed a strong
desire to enter into a collaborative and cooperative memorandum with PWRI.
In response, PWRI—whose mission is to support local governments, train technical personnel, and improve regional technical capacity—sought to actively collaborate and cooperate with Kumamoto City and to accurately ascertain onsite conditions and its research needs. By doing so, PWRI hoped to apply what it finds toward better research.
On this day, Kumamoto Mayor Seishi Kohyama and PWRI Chief Executive Tadahiko Sakamoto signed the memorandum, thereby officially putting it into effect. At a meeting for exchange of technical information that followed, technologies developed by PWRI and projects being implemented by Kumamoto City were presented, and problems faced by Kumamoto City in its civil-engineering projects were classified as shown below. This classification led to enthusiastic information exchanges between municipal engineers and PWRI researchers toward resolution of these problems.
1 Techniques for effective maintenance and management of road structures
2 Ecological engineering for river improvement and nature restoration
3 Effective and efficient maintenance and management of sewerage facilities
Although this memorandum with Kumamoto City is the first that PWRI has entered into with a local government, PWRI hopes to further enhance its collaborative and cooperative undertakings in a way that bring mutual benefits.
(Contact: Construction Technology Research Department)
Avalanche Disaster Prevention Seminar
Report on “Recent Snow Avalanche Disasters and Frontline Research”
 Keynote lecture by Professor Kouichi Nishimura of Niigata University |
 Avalanche Disaster Prevention Seminar in Akita (Japanese Only) |
On Nov. 30th, 2007, the Snow Avalanche and Landslide Research Center and
Snow and Ice Research Team in CERI joined hands to host an Avalanche Disaster
Prevention Seminar titled “Recent Snow Avalanche Disasters and Frontline
Research” in Akita City. The seminar was held with the cooperation
of Akita Prefecture, and was scheduled in advance of “avalanche disaster
prevention week” in December.
Targeting persons in charge of relevant matters, such as administrators
concerned with snow protection, the seminar was the first ever held for
the purposes of deepening understanding of the characteristics of recent
snow avalanche disasters and snow-avalanche countermeasures (taking into
account lessons learned from the heavy snowfall of 2006), presenting up-to-date
research in Japan and overseas, and considering future snow-avalanche countermeasures.
Professor Kouichi Nishimura of Niigata University gave a keynote lecture
titled “Important Points in Disaster Prevention as Considered based
on Recent Snow Avalanche Disasters.” Following the professor's lecture,
four members of the PWRI staff reported the results of recent snow avalanche-related
research.
This significant seminar was successfully completed with the participation
of 77 people representing a variety of organizations, including 23 people
from national organizations (eight from the Tohoku Regional Development
Bureau, two from the Hokkaido Regional Development Bureau, four from the
Tohoku Regional Forest Office, and nine from the Akita Local Meteorological
Observatory), 27 people from Akita Prefecture, nine people representing
municipalities, 13 people from Sabo Volunteer Associations (NPOs), and
five consultants.
(Contact: Snow Avalanche and Landslide Research Center)
PWRI receives a certificate of gratitude from Niigata Prefecture
 Certificate of gratitude presented by Niigata Prefecture |
 Persons who received certificates of gratitude |
On Nov. 22nd, 2007, the Governor of Niigata Prefecture presented PWRI with
a “certificate of gratitude” for its contribution to recovery
and reconstruction efforts toward affected areas following the Niigataken
Chuetsu-oki Earthquake in 2007.
Certificate presentation ceremonies were held on four occasions in late October (twice at the Niigata Prefectural Government offices and twice in Tokyo). The certificates were presented to organizations that helped in the rescue/relief of victims or contributed to recovery/reconstruction efforts toward affected areas. A total of 254 organizations were recipients (there were 28 recipients at the fourth ceremony, at which PWRI was a participant).
In his greeting, the Governor said, “The Chuetsu-oki Earthquake was a reverse-fault earthquake with a magnitude of 6.8. Unlike previous Chuetsu earthquakes, which primarily damaged public facilities, this earthquake caused liquefaction that resulted in significant damage to residences, which are personal assets. We expect to have all people currently staying in evacuation centers moved to temporary housing by the end of the year, and we intend to complete reconstruction as soon as possible. I thank you for your contribution to this effort.”
Major activities which were undertaken by PWRI involved provision of advice on damage surveys, emergency measures, and reconstruction methods, they also contained technical advice and guidance on reconstruction of collapsed bridges, etc.
Visit to PWRI by Senior Vice Minister Hirai
 Briefing held in the Chief Executive’s office (Senior Vice Minister Hirai is seated in the center.) |
 Senior Vice Minister Hirai (far left) in a dialog with visiting international researchers |
This past Feb. 7th, Senior Vice Minister of Land, Infrastructure, Transport
and Tourism Takuya Hirai visited five organizations in Tsukuba that are
affiliated with MLIT.
Mr. Hirai visited PWRI first, arriving by car. After receiving a briefing of PWRIfs activities in the Chief Executivefs office, Mr. Hirai engaged in a dialog with visiting international researchers. Finally he visited the Three-Dimensional Large-Scale Shaking Table (Vibration Laboratory).
The dialog was held at the International Centre for Water Hazard and Risk
Management (ICHARM). Five research specialists from foreign countries were
present. To begin, Acting director of ICHARM Akira Terakawa offered a greeting
and then introduced each of the research specialists. After that, the Senior
Vice Minister offered his own greeting before giving encouragement to the
researchers, saying in English, “I imagine you must overcome many
difficulties to live in a foreign country, but nevertheless I pray you
will have great success in your activities both at ICHARM and in your own
countries after your return home.”
Finally, a meaningful dialog that went over the allotted time took place.
The dialog included a message of gratitude that Dr. Rabindra Osti delivered
on behalf of the visiting research specialists.
Following the dialog, the Senior Vice Minister Hirai viewed ICHARMfs auditorium,
which was completed at the end of Oct. 2007, and then boarded a microbus
to see the Three-Dimensional Large-Scale Shaking Table. There, director
of the Earthquake Disaster Prevention Research Group Osamu Matsuo explained
the main functions of the testing facility, the purposes for which it is
used, and how the achievements of research conducted at the facility directly
contribute to seismic reinforcement of bridges.
The Senior Vice Minister Hirai then traveled to his next destination, the
National Institute for Land and Infrastructure Management. He completed
his tour of the five Tsukuba organizations by later visiting, in turn,
the Building Research Institute, Meteorological Research Institute, and
Geographical Survey Institute.
Follow-up seminar for flood hazard mapping in Guangzhou
 Keynote lecture by Mr. Manzul Hazarika of the Asian Institute of Technology (AIT, Bangkok) |
 A view of the seminar |
The second “East&Southeast Asia Regional Seminar on Flood Hazard
Mapping, 2008” was held from Jan. 30th to Feb. 1st, 2008, in Guangdong
Province, China. It was co-hosted by the International Centre for Water
Hazard and Risk Management (ICHARM) and the Office of State Flood Control
and Drought Relief Headquarters, China, with support from the Japan International
Cooperation Agency (JICA).
The seminar was held as part of follow-up to region-focused training on
“flood hazard mapping” that is being provided by ICHARM. The
first seminar took place in Feb. 7th to 9th, 2007 in Kuala Lumpur, Malaysia.
For this seminar, trainees from East and Southeast Asian countries (China,
Vietnam, Cambodia, Malaysia, the Philippines, Indonesia, Laos, and Thailand)
who had completed the training (hereinafter “ex-trainees”)
were invited to participate in the seminar (circumstances prevented the
ex-trainee from Vietnam from attending). The seminar served as a venue
for reporting on activities related to flood hazard map preparation and
dissemination, sharing successes achieved and problems confronted by the
trainees in their work as well as knowledge and experience regarding application
of the flood hazard maps that are needed in each country, and fostering
discussion toward problem solving. The seminar further sought to make future
training in flood hazard mapping more effective by collecting training-related
opinions and requests.
A major focus of the seminar was to examine, based on circumstances in
each country, the progress that ex-trainee-led projects that were reported
at last year’s first seminar had achieved and the kinds of problems
they were confronting. In all of the countries, led by China and Malaysia—both
of which made significant progress from the previous year—flood hazard
mapping projects were being promoted together with overseas organizations,
or flood hazard maps were being prepared through discussions with local
residents. And in all countries, ex-trainees were working as project members
to promote the preparation and dissemination of flood hazard maps.
It should be noted that many countries expressed the opinion that preparation of guidelines, such as manuals for flood hazard mapping, must be added to data maintenance and technical acquisition as a topic each country must address in the future as it prepares flood hazard maps.
(Contact: International Technical Exchange Team, ICHARM)
PWRI NEW Technology Showcases held
 Presentation (Nagoya) |
 Presentation (Hiroshima) |
 Panel exhibition and technical consultation |
The PWRI New Technology Showcases were held in Nagoya on Dec. 6th and in Hiroshima on Dec. 14th, 2007.
Held to widely disseminate achievements of PWRI research, the showcases
use a presentation-like format to introduce useful new technologies that
were obtained through joint research projects with private companies and
others to civil engineers associated with civil engineering projects for
roads, rivers, etc. The showcases also present exhibits on new technologies
utilizing panels, models, and other media, and offer technical consultation.
In regional cities outside Tokyo, PWRI holds showcases with the cooperation
of the Japan Civil Engineering Consultants Association (JCCA). For these
showcases, PWRI selects and presents new technologies having high demand
from JCCA's regional branches.
Both days of the showcases attracted some 300 participants. While most of these people were from private companies, there were also officials of MLIT, local governments, and public utility corporations present.
At both venues, the showcase began with a lecture titled “R&D
and diffusion of results by PWRI” by Kiyoshi Minami, Director of
Construction Technology Research Department. The following new technologies
were then presented:
- 3H(Hybrid Hollow High Pier) method: The method for more efficient and quicker building of high bridge piers of 30 meters or taller
- Invairowan method: The method for easy removal of old coating film of steel structures
- High Grade Soil methods: The methods for effectively using low quality soil generated at construction sites
- ALiCC method: The method that efficiently hardens and strengthens soft and weak ground
Participants intently listened to the presentations and proactively exchanged opinions at the exhibition and technical consultation held simultaneously in a separate room. We believe such interest is evidence that the participants gained a firm understanding of the presented technologies.
(Contact: Construction Technology Research Department)