Abstract
The determination of the type of bridge-foundations which is most suitable to the condition of soil has important effect not only for the total cost of construction, but the term of the construction works, and also for insuring the safety at field excurtion.
In HOKKAIDO, the lowlands belong to the big rivers are characterized with the silty, peaty and water contented clay. These grounds are spread over this island everywhere. In this paper we deseribed the typical bridge-foundations that we developed or improved on these grounds. (1) Radically obliquely combined steel piles-foundation: Analysis and field experimentation. (2) Open caison: Sinking execurtion works with-out any weights. (3) Open caison enclosed with joined steel pipe piles: Analysis and laboratory model test. (4) Open caison enclosed with field executes, extremely deep concrete wall: Analysis and excurtion.
