1981 Volume 19 Issue 12 Pages 36-42
The reinforced concrete dome built on the north breakwater in Port of Wakkanai, Hokkaido, Japan, is the world's unprecedented harbor structure having a waterbreaking function and a passageway. The dome, supported with circular columns, also has boasted of its aesthetic structure. However, over 40 years since its completion in 1936, cracks, separation, and falling-off of its concrete, and corrosion of its steel reinforcement, have developed and to cope with such defects, partial repairs have been performed. However, because of its markedly progressing aging, a measure was taken to prohibit the traffic on its passageway since 1976. In recent years, along with the increased necessity for ferry-boat passengers to use the passageway, studies have been made as to how the dome should be renovated and over a period of 3 years from 1978 its demolition and renovation were carried out. This paper reports the outlines of the various investigations conducted prior to starting the works, and the design and works of the new dome.
