Geotechnical aspects of current underground construction in Japan

The Japanese National Committee for TC28 has produced a committee report on current underground construction activities in Japan, including the technologies of braced excavation and tunneling. This report is based on technical papers and available construction records from the past decade. In the field of braced excavation, the topics of proximity construction, excavation machines for braced walls, deep shaft excavation, and groundwater flow preservation measures have been selected and introduced, along with some case records. In the field of tunneling, statistical data on tunneling in Japan has been assembled from published data and questionnaires. Several case records using current shield tunneling and urban NATM methods are described. Finally, damages to underground structures due to the 1995 Hyogoken-Nanbu (Kobe) Earthquake are summarized, and new earthquake-resistant designs for shield tunneling and other technologies are introduced.