The construction of artificial fish reef is one of the important problems for establishment of extensive fishery grounds, and is now accounted for one thirds of the Governmental works under the coastal fishery ground improvement and development policy which was set forth in 1977.
This paper describes (1) the structure of artificial fish reef and fish gathering effect in the current environment,(2) the dynamic computation for planning of the safety fish reefs,(3) the relationship between the movement of current and the behavior of fishes in the sea with different temperature, salicity and osmotic pressure, and (4) as for the engineering problems, the shock to be occurred when the fish reef is placed on the seabottom and the external forces after establishment, such as the waves and the hydromechanics.

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This is the interim report of steel fiber reinforced concrete test pavement construction at Kuroiso Bypass,national HWY route No.4.
The full scale test pavement construction using steel fiber reinforced concrete was actually carried out on job-site by set-form concrete paving machines from 1975 to 1978.
Four design types of pavement were constructed and length of concrete slabs were changed.
In this report, flexural strength of steel fiber reinforced concrete (within one year), spacing and distribution of steel fiber, density of concrete, behavior of slabs and skid resistance of pavement etc. are reported.

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This paper describes a techniques to construct diaphragm walls, using precast concrete panels.
The process of this technique is the same as that of the ordinary cast-in-situ diaphragm wall construction technique, upto the step of trenching by the use of bentonite slurries, but the futher steps of this technique is to place a precast concrete panel in the slurry trench, thereafter, to solify to the farm of hard clay by the addition of a gelling agents to the bentonite slurries.
This technique is characterized in obtaining excellent quality of diaphragm wall, accuracy of dimension, watertightness, and so on.

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