As for the waterfront development m the Osaka Bay area, Japan, many onshore and offshore projects have been carried out and are in progress or planning In this paper, first, the ground condition of the Osaka Bay area is outlined from geological and geotechnical viewport then, six major onshore and offshore Projects in progress are selected and outlined. Finally, geotechnical topic on waterfront developments m the Osaka Bay area are summarized and discussed.
In Japan, the area where social activities can be carried out is about 100000 km2, which is less than thirty percent of the total area, while the population is more than 120 million it is mevltable, therefore, that there is not enough of the necessary action space especially m such large-scale cities as Tokyo and Osaka. Recently, intense interest has been shown towards new frontier space development, such as waterfront and underground space which is called "geofront" in Japan. As for the waterfront development m the Osaka Bay area, many onshore and offshore projects are m progress or planning, as shown in Fig. 1 The Osaka Bay is oval-shaped, which has major and minor axes of about 60 km and 30 km respectively. Many large-scale man-made Islands including the Kansai International Airport to open in September, 1994, have been constructed and are under construction or planning, especially along the shoreline of northeastern part of the Osaka Bay to provide more space for social activities and industrial and commercial developments of the Kansai Region which includes the cities of Osaka, Kobe, Kyoto, Nara and Wakayama. These reclaimed man-made Islands are usually constructed on the superficial soft marine clay of Recent Deposit, underlain by lower medium to stiff PleIstocene clay layers sandwiching sand and gravel layers.