Dam Grouting Work at Kurashiki in Okayama

This project was constructed as Japan's first national stockpiling base for liquefied petroleum gas (LPG) stored at room temperature and high pressure in underground rock formations (Kurashiki National Oil and Gas Stockpile Base). The Water-sealed type underground rock cavern tank system is used in this stockpiling base.

The project involved constructing a large cavern 640 meters long, located 200 meters beneath the seabed in Kurashiki City, Okayama Prefecture. Working under high water pressure proved to be extremely challenging. Moreover, the water-sealed type underground rock cavern tank system required a very low permeability, less than one-tenth of that of conventional dam grouting.

We developed new technologies such as dynamic injection methods and early-setting ultra-fine particle cement, successfully completing the project without any accidents.

(Location: Kurashiki, Okayama)