PWRI News

Award of Excellence and Award of Selection Chairman won at the 15th Infrastructure Technology Development Awards

 Award of Excellence
   Left:Takahiro Sayama, Senior Researcher
   Center:Akihiro Ohta, Minister of MLIT
   Right:Kuniyoshi Takeuchi, Director of ICHARM


 Award of Selection Chairman
   Left:Hidetoshi Kohashi, Former Team Leader
   Center:Hideo Nakamura,
President of Tokyo City University
   Right:Hiroaki Miyatake, Team Leader


 Commemorative Shield from Minister
of MLIT

15th Infrastructure Technology
Development Awards
Award of Excellence
Rainfall-Runoff-Inundation Model (RRI Model)
To Public Works Research Institute
From Akihiro Ohta, Minister of MLIT




  The “Rainfall-Runoff-Inundation Model (RRI Model)” developed by the Water-related Hazard Research Group of the International Centre for Water Hazard and Risk Management (ICHARM), has won the Award of Excellence at the 15th Infrastructure Technology Development Awards (organized by the Japan Institute of Country-ology and the Engineering/Coastal Development Institute of Technology, and sponsored by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT)). The “ALiCC Method” developed by the Construction Technology Research Team of the Geology and Geotechnical Engineering Research Group has also won the Award of Selection Chairman. The ceremonies were held at the Tokyo International Forum on Jul. 5th, 2013.

  This award is designed for the outstanding new technologies developed roughly within last five years and put into practical use within last three years, in the fields of planning/design methods, construction methods, maintenance, materials/products, machinery, electricity/communications or application of traditional crafts, related to housing, infrastructure and land management, aiming to encourage technology developers in research and development and raise technology levels in the above fields.

  The “Rainfall-Runoff-Inundation Model (RRI Model)” (Head Technology Developer: Senior Researcher Takahiro Sayama) is a forecasting model which can analyze a basin-scale process from rainfall to flood inundation, focused on large-scale floods in various parts of the world. Existing forecasting models separately analyze rainfall-runoff from mountainous areas and flood inundation in plain areas. However, these models are not always suitable for quick and appropriate forecasts of the rainfall-runoff-inundation phenomena complexly interacting with both processes. The RRI Model can be suitable for forecasts of large-scale floods. In 2011, it was used for the appropriate forecast of the flood inundation in the Chao Phraya River basin in the Kingdom of Thailand.

  The “ALiCC Method” (Head Technology Developer: Former Team Leader Hidetoshi Kohashi) is a design method for constructing an embankment on a soft ground, that allows greater intervals between end-supported cement piles by rationally calculating the load on these piles. Compared to conventional design methods, it significantly reduces construction costs by allowing fewer piles. Moreover, it still assures not only stability and subsidence prevention of the embankment but also helps prevent distortion of the surrounding ground due to subsidence of the embankment, as the piles are constructed uniformly under the embankment. This method has been successfully applied to 30 different structures including the Ariake Sea Coastal Road of Fukuoka Prefecture and Route 8 Maibara Bypass of Shiga Prefecture.

  More applications of these technologies would expectably contribute to a better life through construction and management of infrastructure.



(Contact: Construction Technology Research Department)

PWRI - NIMS Partnership Agreement
- Agreement Gives Impetus to R&D that Improves the Efficiencies of Social Infrastructure -

  


Photo: PWRI Chief Executive Uomoto (left) and NIMS President Ushioda (right)


  On Jul. 23rd, 2013, a new partnership agreement links the work of the Public Works Research Institute (PWRI; Chief Executive Taketo Uomoto) and the National Institute for Materials Science (NIMS; President Sukekatsu Ushioda).

  In past, the two organizations have often worked on multiple exchanges to share capabilities and join research topics. In the work to solve issues of Japan's social infrastructure, NIMS's basic technology on structural material has been combined with PWRI's expertise in social infrastructure maintenance and renewal. Collaborative research has been especially strong in using bridges owned by PWRI to study removed structural members reclaimed from the market.

  Under the partnership agreement, PWRI and NIMS can now maximize collaborate efforts involving their respective fields of expertise, research capability and talent pools. Not only does this promote the mutual growth of PWRI and NIMS, but it also contributes to society by providing a strong impetus to R&D that improves the strength and efficiency of social infrastructure and helping to resolve the consequent social issues.

  The agreement focuses on the following fields for partnership and collaboration:

     (1)  Promotion of R&D in fields of mutual interest

     (2)  Shared use of research facilities and equipment

     (3)  Mutual exchange including research exchange among researchers and teams

     (4)  Joint efforts to improve information dissemination

     (5)  Other matters required to achieve the objectives of the agreement


  PWRI possesses the technology to evaluate and repair social infrastrctures and the structures in actual use, offering the capability to test in real environment. NIMS, on the other hand, owns steel material developed in-house, as well as evaluation and repair technology of various structures.

  Through the partnership agreement, PWRI will develop greater longevity and safety for social infrastructure, accessing to the state-of-the-art material technology, which NIMS analyzes real structures and conducts evaluations in real environments. This is expected to accelerate R&D towards practical application.



(Contact: Planning and Management Division)

Road Technology Seminar in Myanmar

 Fig. 1 Ayeyarwady Delta region,
Myanmar (click to enlarge)


 Photo 1 Road conditions
in the Ayeyarwady Delta


 Photo 2 Gravel delivery by barge



  Over Jun. 13-14, 2013, JICA sponsored a hand's-on road technology seminar in Yangon, Myanmar. The event was supported by the attendance of PWRI's Dr. Miyatake, Leader of the Construction Technology Research Team, and Dr. Kubo, Leader of the Pavement Research Team. The seminar plays an integral role in JICA's Project to Improve Road Technology in Disaster Prone Areas and has as its goals: (1) to advance practical skills and knowledge among local road engineers through pilot projects and other work in the Ayeyarwady Delta; and (2) to improve technical standards and process manuals for road design and construction. The seminar included site visits to support the first goal (1), and presentations and explanations to support the latter goal (2).

  Located in the coastal area southwest of Yangon, the Ayeyarwady Delta generally consists of soft ground and often suffers severe damage from cyclones and heavy rainfall (Fig. 1). Particularly serious flood damage was inflicted by Cyclone Nargis in 2008. Photo 1 shows representative Ayeyarwady Delta road conditions. Since the site visits were appropriately scheduled during the rainy season, the region's simple gravel roads were often muddy, only allowing vehicles to proceed at barely 10km per hour. The initial solutions considered by local engineers focused on hardening, such as cement stabilization of the subbase and subgrade; however, strengthening of the subbase and subgrade alone was unlikely to provide sufficient bearing capacity since the site conditions showed water levels at higher than not only the subgrade but the subbase as well. The need was for a more fundamental solution, e.g., river improvement. The prevailing practice is to outsource rainy season road management to the local residents, who make emergency repairs of the road surfaces by crushing gravel delivered by river barge (Photo 2).

  Following the site visits, at the Yangon seminar, many participants expressed high hopes for the application of Japanese technology, with a few assuming that problems could be solved simply by direct technology imports or aid. It was repeatedly explained that an understanding of site conditions was key to resolving the issues long term.

  The project will continue through June 2015. Road engineers of both nations will work together in further exchanges to both advance local skills and practices, and to improve standards and manuals as are the goals (1) and (2) above. Through understanding the value of this project, PWRI will continue its support for site visits and other efforts.



(Contact: Pavement Research Team)

Support on Restoration Method of Wastewater Treatment Plants Seriously Damaged by Tohoku Tsunami in the Great East Japan Earthquake 2011

 Wastewater treatment plant seriously
damage by tsunami


 Fig. 1 Relationship between sodium
hypochlorite dosage and concentration
of coliform group bacteria
(click to enlarge)


 Fig. 2 Relationship between sodium
hypochlorite dosage and concentration
of coliform group bacteria
(click to enlarge)



  In March 2011, all of the wastewater treatment plants located in low-flat land along coastal area in the northeastern area of Japan were seriously damaged by the tsunami generated by the Earthquake; they quickly lost a capacity for wastewater treatment function. The restoration of wastewater treatment plants seriously damaged hasn't been completed yet. Meanwhile, even as recovery of water supply services to the disaster areas extends, wastewater discharged from households and other users flows into wastewater treatment plants. As for their restoration during influent sewage increasing at every moment, the municipalities had to take appropriate combinations of stepwise reconstruction and operations for acquiring the wastewater treatment function from primary level to secondary level in consideration with each plant's damage and its water quality requirement in the received water bodies such as rivers and sea.

  In the early stages of emergency restoration, only sedimentation and chlorination were applied to wastewater treatment. However, these method were insufficient to the achievement of the effluent standard of final effluent, it concentration of coliform group bacteria more than 3,000CFU/ml for hygienic safety in Japanese standards. With requests coming from the municipalities which manage the wastewater treatment plants, Public Works Research Institute launched studies to improve effect of disinfection, conducting both field surveys and experiments, to try to reduce the presence of coliform group bacteria in the final effluent.

  Fig.1 shows some results of the studies. There were distinct differences in the effectiveness of disinfection to coliform group bacteria between wastewater treatment systems which had applied, for the period that long and short period of continuance processing on executed by the only sedimentation processing. The difference was caused to the amount of sludge accumulated in the final sedimentation tank over the course of time. Therefore, in the early stage when only sedimentation was applied, the withdrawal of sludge from the sedimentation tank was important.

  In the next stage, we evaluated applications of roughing aeration and biological treatment using microorganisms (activated sludge) to contribute for wastewater treatment. At present, the water quality of the final effluent has been significantly improved with reductions in the concentration of coliform group bacteria using less dose of sodium hypochlorite for disinfection. (Fig. 2)

  In the technical assistance to the municipalities having the damaged wastewater treatment plants, we were able to ascertain that deterioration of the water quality of the restoration at the stage in wastewater treatment seriously influenced the efficiency of disinfection. We were thought that it was important in the near future to proceed to clarify the issues obtained throughout these supports, to conduct a research on the stepwise restoration technologies to achieve an efficient disinfection, and to propose of a solution to the problem.



(Contact: Recycling Research Team)

FY 2013 “Tsukuba Little Doctor” Open House

 Learning how a tsunami moves up a river


 A sharper slope than expected.


 Children learning how debris flow happen




  Tsukuba Little Doctor is now PWRI's annual public outreach event held in a joint effort with the National Institute for Land and Infrastructure Management (NILIM). This summer, children were able to participate on three consecutive Fridays: Jul. 26th, Aug. 2nd and 9th. Despite the heat wave, the three day event drew 708 participants including children on summer vacation and their parents.


  On Jul. 26th, participants saw NILIM's tsunami generation system where they watched a reproduction of a tsunami ascending a river; they also saw a non-destructive inspection of rebar arrangements encased in a concrete construction. At the test track, they rode a vehicle at high speed before they experienced the steep slope of the track on foot.

  On Aug. 2nd, participants visited the road noise control laboratory to experience just how sound echoes differently in a reverberation chamber and in an anechoic chamber. A simple slide presentation on “Life Today and Water” introduced the important role of water purification systems and the potential for health problems without such systems. The opportunity to visit the test track was again offered.

  On Aug. 9th, the participants had a chance to look into the future with a glimpse at the power supply system for a moving electric vehicle. Through an explanation using a model, they also learned how landslides happen and countermeasures are taken. Again, the popular test track option was made available.


  Despite limited time windows, PWRI and NILIM provided a range of sessions introducing modern civil engineering to children. We hope the better understanding will support the children through their lives.

  Though the time available had been limited, we hope this direct experience of civil engineering technology will surely remain in their memories even as they grow into adults. At PWRI, we would like to continue “Tsukuba Little Doctor” and other similar events open to the public for their better understanding.



(Contact: General Affairs Division)