2022 Innovative Technique Award
1. Development of the Net Buffer Method for suppressing internal erosion and collapse behind seawalls and quaywalls through caisson joint wave reduction
- Shinji Sassa
- Osamu Ishizaka
The Net Buffer Method substantially suppresses the risks of internal erosion and collapse behind seawalls and quaywalls by caisson joint wave reduction. Caisson joints may fail due to repeated waves that pass though the joints. The new method, in which a net fiber material is installed within the joints, is capable of reducing such caisson joint waves by more than 80%. Unlike previous countermeasures, it can autonomically adjust to changes in the configuration due to continued wave impacts and earthquakes. This new technology has proven itself effective in suppressing the occurrence of collapse at diverse caisson structures including Major Ports and Strategic International Ports in Japan.
2. Development of quality attainment technology for concrete structures by accelerating PDCA cycle utilizing digital data (CONCRETE@i🄬)
- Shuji Yanai
- Kenzo Watanabe
- Shuji Matsumoto
- Kohei Mizuno
- Akira Hosoda
CONCRETE@i🄬 is the system that assists in planning appropriate concrete works and manages the fresh concrete conditions and construction progress at each process by "digitizing and visualizing" in real time. With this ICT management tool that reflects the proposed plan, anyone can instantly grasp the situation and make appropriate decisions and countermeasures, resulting in eliminating construction troubles and attaining the quality of concrete structures. In addition, PDCA cycle based on data can improve the quality of concrete structures. We will analyze the implicit knowledge of expert engineers with accumulated data, standardize construction methods, and pass them to the next generation.
3. Development of Unmanned Laser Decontamination System
―Realization of High Contaminated Flange Tank Dismantling at Fukushima Daiichi Nuclear Power Plant―
- Fumio ITO (Taisei Corporation)
- Takaharu Goto (Taisei Corporation)
- Hiroshi Nakamura (TOYOUNION)
- Tomohiro Ogawa (Tokyo Electric Power Company Holdings)
- Naoki Maeshiro (Tokyo Electric Power Company Holdings)
- Haruo Nagamine (Taisei Corporation)
This development is an automatic laser decontamination method that can remove radioactive substances and anti-corrosion coatings before the dismantling of a flange tank. In this development, laser light irradiates the inner surface of the tank to reduce the amount of adhered radioactive material (decontamination) to achieve suppression of dust dispersion and reduce the radiation exposure of workers. As a result, the safety of workers was improved, and environmental impact was reduced through the reduction of secondary radioactive waste generated. Furthermore, by robotizing, unmanned decontamination of high-dose tanks that were previously impossible to dismantle was achieved.
4. Development of high-strength environment-friendly concrete with significantly reduced CO2 emissions and practical development by secondary productization
- Junichi MATSUMOTO
- Kenichi HORIGUCHI
- Toshihide KIMURA
- Satoshi HASHIMOTO
- Fumihiko SUGAI
- Tatsuya YAMANASHI
- Shin SAWAKAMI
Toward achieving the realization of carbon neutrality by 2050, we have commercialized a secondary product made of high-strength, environmentally friendly concrete that does not use Portland cement and uses a large amount of ground granulated blast furnace slag, a by-product of steelmaking.
In this technology, we have established a method of selecting a mixture that has the workability and strength development required for secondary concrete products, also less variation a quality at any factories.
Furthermore, the application of the secondary products manufactured based on this in the actual construction greatly contributed to the reduction of CO2 emissions and reduction costs.
5. Development of Construction 3D Printing Technology using Fiber-Reinforced Cementitious Composites
- Hiroki Ogura
- Shinya Yamamoto
- Hiroyuki Abe
- Ryu Kikuchi
- Reina Nakanishi
This technology can fabricate high-quality laminated members by extruding and layering materials through a digitally controlled nozzle. The material to be printed is a fiber-reinforced cementitious composite developed for 3D printing. By using this material, we have succeeded in integrating the interface of each printed layer, which was considered a weak point in existing 3D printing technologies. As a result, it is now possible to print large-scale members over 2m in height with excellent mechanical characteristics and durability. The laminated members have high toughness due to the reinforcing effect of the fibers, achieving a bending strength of 14 MPa. This technology has been evaluated for its ability to print high-strength, high-toughness members with little variations in quality, and has been applied at several sites.
