Dokaiwan Conveyor Tunnel
HEIGHT: 4.55 m
WIDTH: 8.2 m
DEPTH AT BOTTOM OF STRUCTURE: 15.9 m
TOTAL IMMERSED LENGTH: 1,283 m
ENVIRONMENTAL CONDITIONS:
Dense navigation. Very rough seas in winter season. The platform was designed to be
stable in typhoon winds of 150 KPH.
FABRICATION METHOD:
Two elements were fabricated in one cycle in a drydock.
Heavy end-struts were installed in the casting beds to
limit growth due to thermal expansion during casting to
less than 5 mm.
WIDTH: 8.2 m
DEPTH AT BOTTOM OF STRUCTURE: 15.9 m
TOTAL IMMERSED LENGTH: 1,283 m
ENVIRONMENTAL CONDITIONS:
Dense navigation. Very rough seas in winter season. The platform was designed to be
stable in typhoon winds of 150 KPH.
FABRICATION METHOD:
Two elements were fabricated in one cycle in a drydock.
Heavy end-struts were installed in the casting beds to
limit growth due to thermal expansion during casting to
less than 5 mm.
Kita-Kyushu,,
Japan
13 - 80 m 3 - 81.04 m
1283m
15.9m
Project construction
1972-04-30
16
4.55m
8.2m
Rock bed was exposed at the depth of-10 m along about 300 m in southern approach.
To lessen amount of rock excavation at this part, the slope of approach sections have
a steep gradient.
To lessen amount of rock excavation at this part, the slope of approach sections have
a steep gradient.
Two elements were fabricated in one cycle in a drydock.
Heavy end-struts were installed in the casting beds to
limit growth due to thermal expansion during casting to
less than 5 mm.
Heavy end-struts were installed in the casting beds to
limit growth due to thermal expansion during casting to
less than 5 mm.
At mooring berth 9 km
from the site. Concrete
curing took place at the
outfitting dock.
from the site. Concrete
curing took place at the
outfitting dock.
Dense navigation. Very rough seas in winter season. The platform was designed to be
stable in typhoon winds of 150 KPH.
stable in typhoon winds of 150 KPH.
By a semi -submersible jack-up platform, especially fabricated for this project at dock
yard. Crushed stone and slag were used for placement ballast.
yard. Crushed stone and slag were used for placement ballast.
Rigid connection with rubber
gasket.
gasket.
Elements were covered with 6 mm thick steel plate.
A crushed stone bed (stone e the thickness of 0.7 m
and a width of 9.3 m. Screeding was operated from the jack-up platform.
and a width of 9.3 m. Screeding was operated from the jack-up platform.
Riprapping at both sides; backfilled by sand. Protective crusher-run layer was placed
over tunnel.
over tunnel.