●Kawamata dam using bedrock PS anchor

Kawamata Dam was constructed in 1966 to construct an efficient arch dam that can store a large amount of water with a small volume of concrete, making the best use of the surrounding topography. To increase the strength of the bedrock that supports the arch action, bedrock improvement work using bedrock PS anchors, which was the most advanced technology of those time, was adopted. The bedrock PS anchor method used for bedrock improvement work was critically acclaimed as an epoch-making construction method at the International Commission on Large Dams held in Edinburgh, England in 1964. After a half-century of its construction, Kawamata Dam renovation work began in 2017. This time, renovation work for reinforcement of the bedrock using anchors will be installed between the existing anchors that were installed during the construction of the dam.
In July 2020, the planned anchor construction was completed successfully, but there were many challenges along the way. We worked in a fumbling condition, including technical issues such as anchor design, drilling, installing, grouting, development of technology associated with tensioning work, and installation of anchor scaffolding for steep slopes, as well as cost performance issues. Also, since I had no experience in constructing a dam in service, I paid close attention to the construction process so as not to interfere with the drinking water supply for residents in the downstream area, agricultural water supply, and infrastructure such as power generation.
After completing these issues one by one and asking for the cooperation of experts in bedrock PS anchors, all of the knowledge and technology available in Japan and overseas was mobilized, and the completion of the construction work finally was in sight. Furthermore, as a result, we were able to obtain various knowledges that will serve as a standard for the bedrock PS anchors.

●Training of young engineers