ARTIFICIAL ISLANDS RECENTLY CONSTRUCTED IN OSAKA BAY. JAPAN

최근 일본 오사카만에 건설된 세개의 인공섬

An attempt has been made to summarize some of the unique geotechnical problems encountered during construction of a few large man-made islands recently completed off the coast of Osaka Bay, Japan. Large settlements appear to be the most serious problem both during and after construction. Settlements due to consolidation of a thick layer of soft alluvial clay that constitutes seabed seem to virtually cease within a relatively short period of time when vertical drains are installed adequately prior to fill placement. Settlements due to compression of underlying thick diluvial deposits consisting of layers of stiff clays interbedded with coarse-grained soils, however, continue over a prolonged period of time and call for special provisions for structures built on the artificial islands to cope with relatively large future settlements. Although accurate settlement prediction is not possible, it is both technically and economically feasible, nevertheless, to construct large-scale islands. Partjcularly attractive and promising is creation of sizable new areas for various purposes, immediately adjacent to highly-developed, densely-populated cities situated along the coast such as those around Osaka Bay.