those in normal, and the wire of packed stones applied are provided with special galvanization treatment.
The construction work of the soft ground dike was commenced in 1987. In the same year 10 units of dike were fabricated and installed, and 47 units were fabricated in 1988 and installed in 1990, thus the total of 57 units in service by now, 1991, with the total length of some 858 m.
In comparison of economy with the conventional type of gravity breakwater requiring foundation improvement, the work cost is greatly reduced to 1/5 to 1/7.
Furthermore, field static horizontal loading and repeated loading tests were conducted in 1990 with long-pile soft ground dikes, wherein piles driven down from the dike bottom were made longer and pile rigidity made lower, so that even worse ground conditions than now, which are very likely to be expected in the future, can be handled. In the long-pile soft ground dikes the two rows of piles at front and back exhibited uniform resistance against horizontal external force, consequently reducing the bottom slab inclination. Thus, the resistance characteristics of long-pile soft ground dike were stable. It was confirmed as well that repeated load
