1999 Volume 9 Pages 119-124
About 20 km length of the Kyushu Shinkansen route passes through on pumice-flow deposit Shirasu area in Kagoshima prefecture. The tunnel sections which total length is about 7 km are proposed in the Shirasu under the groundwater. Since few, Shirasu tunnels for railroad under the groundwater have constructed in Japan, design and construction method of the Shirasu tunnels should be developed.
This paper introduces ground improvement method with blast-furnace slag to construct permanent permeable roadbed for the Shirasu tunnels. It is expected that the Shirasu tunnels can be constructed safely and economically by using this method.
