Livecon Engineering Co., Ltd.
Water is charged in two steps to stabilize and raise the quality of concrete. The quality of concrete is significantly affected by timing and sequence of charging materials as well as mixing duration.
IHI Construction Materials Co., Ltd.
The shell of a tunnel is constructed with elements (square steel tubes) to complete the tunnel structure. Excavation and finishing work are then performed on the inner part of the shell all at once to complete the tunnel. This article describes an ideal tunnel construction method that ensures safety, short construction period, and high cost efficiency, and that does not interfere with traffic.
IHI Construction Materials Co., Ltd.
When a previously constructed tunnel is internally reinforced with high-performance PCL (Precast Concrete Lining) panels, the diameter of the tunnel is reduced. To address this issue, IHI Construction Materials Co., Ltd. has developed a construction method intended to increase the strength and reduce the thickness of part of a PCL panel to make it possible to reinforce tunnels without having to lower the roadbed.
IHI Infrastructure Systems Co., Ltd.
Recently, stainless steel is being used more extensively as a material for sluice gates. Even if made of stainless steel, however, some parts of sluice gates can corrode. We have therefore developed an eco-friendly passivation treatment method that allows passivation treatment to be conducted at factories and construction sites to improve the corrosion resistance of stainless steel. We then confirmed the effectiveness of new treatment method on actual sluice gates.
3. Technical Papers
SUGIMURA Makoto, NAKAYAMA Masaaki, MUTAGUCHI Takusen, SUGIYAMA Naoya,
Large scale suspension bridges are very important infrastructures for supporting national economic activities. However, recently regarding suspension bridges that were built more than 30 years ago, the decline in durability due to local damage from aging is a concern. Since replacing suspension bridges is very costly, it is common and reasonable to try prolonging bridge lifespans by repairing and reinforcing the damaged part of the bridge. Against this backdrop, projects involving existing suspension bridges for the purpose of increasing the lifespan have been increasing. This report describes three major projects carried out by IHI Infrastructure Systems Co., Ltd. worldwide.
YAMAUCHI Kazunori, FUKUSHIMA Noriaki, TAMURA Hiromichi
In recent infrastructure development, it is required to further utilize existing stocks, and many projects of the upgrading dam are implemented and planned in the water control and water utilization. IHI Infrastructure Systems Co., Ltd. has also participated in several upgrading dam projects and introduces previous experiences from the standpoint peculiar to upgrading dams in order to make reference to similar projects in the future.
KAJIMA Kenji, MIYATA Akira
Social interest in the aging of domestic infrastructure is growing. With many different types and degrees of damage having been found on bridges along the Metropolitan Expressway — which has a network exceeding 300 km in length — because they have aged under the severe environment caused by heavy traffic, various countermeasures have been implemented. In addition to continuing to carry out maintenance work, including repairing, reinforcing, and rebuilding bridges along the Metropolitan Expressway, IHI Infrastructure Systems Co., Ltd. has devoted itself to the study of technologies based on its wealth of experience and achievements. In this paper, we describe some of the initiatives that we have introduced and introduce a case study on the maintenance work that we have carried out on Metropolitan Expressway bridges.