The 200 mile extended jurisdiction laws, rising costs of fuel for fishing boat, pollution and land reclamation have reduced the amount of the fishing. Under these situations, the goverment decided to start the“Project of Coastal Fishing Grounds Consolidation and Development”from 1976. This paper discribes the potentiality and performances of the large size artificial reefs and introduce many type of reefs.
This paper deals with the investigation on the relationship between the deterioration of concrete structures and their vibrational characteristics. This is one of our studies for the purpose to apply the field vibrational measurements to the inspection method of structural soundness. The authors have carried out the vibrational measurements twice with about ten years interval by the same measuring method at a RC chimney and a PC bridge. These data were analyzed by the same data processing method. Moreover, a vibrational test was carried out on another PC bridge during its failure test. It is confirmed that the natural frequencies decrease acceleratively as the bridge is losing its loading capacity.
Because of the nature of the structure involved, the structural concrete in nuclear power station construction must be executed with rigid quality control. This paper describes the concrete works executed in the construction of the Fukushima No.2 Nuclear Power Plant for Tokyo Electric Power Co. Ltd., with the discussion centered on quality control in the production and placing of concrete, temperature control in mass concrete and containment concrete.