Staus of the Mizunami URL construction and study on engineering technology

Matsui, Hiroya; Noda, Masaru*; Nobuto, Jun*

Proceedings of ITA-AITES 2011 World Tunnel Congress/37th General Assembly (USB Flash Drive), 8 Pages, 2010/05

JAEA has been conducting research and development at two underground research laboratory projects in crystalline and sedimentary rock respectively. The MIzunami Underground Research Laboratory project (MIU) is the URL being constructed in crystalline rock for geoscientific research and development. The MIU has two shafts, the Main and ventilation shafts, with horizontal drifts between the shafts. Niches were also excavated for geoscientific research at several depths. The depth of the main and ventilation shafts reached G.L.-460 m in November, 2010. The objective of the study on engineering technology was the demonstration of existing engineering technology and any needed improvements for the design, construction and operation of a deep underground structure. The study is on going and it was divided into four subjects, which are demonstration of design methodology, existing and supplementary excavation methods, countermeasures during excavation and safe construction.