Aji River Tunnel
TOTAL IMMERSED LENGTH: 49.2 m
DEPTH AT BOTTOM OF STRUCTURE: 14.9 m
HEIGHT: 7.0 m
WIDTH: 14.0 m
FABRICATION METHOD: The outside 9 mm shell was fabricated at a shipyard. The element was then outfitted with reinforcing steel and concrete at a dock.
ENVIRONMENTAL CONDITIONS: The depth of water was only 5.5-6.3 m. All navigation had to be stopped for nearly 15 hours during placement of the element.
DEPTH AT BOTTOM OF STRUCTURE: 14.9 m
HEIGHT: 7.0 m
WIDTH: 14.0 m
FABRICATION METHOD: The outside 9 mm shell was fabricated at a shipyard. The element was then outfitted with reinforcing steel and concrete at a dock.
ENVIRONMENTAL CONDITIONS: The depth of water was only 5.5-6.3 m. All navigation had to be stopped for nearly 15 hours during placement of the element.
Osaka,
Japan
(Aji river)
49.2m
49.2m
14.9m
Project construction
1944-03-31
1
Two tubes; one lane each with walkway duct
7.0m
14.0m
Structure acts like a bridge. Supported at both ends by abutments constructed by pneumatic caisson method. Single concrete element reinforced with reinforcing steel and rolled steel sections.
The outside 9 mm shell was fabricated at a shipyard. The element was then outfitted with reinforcing steel and concrete at a dock.
In flotation at dockside 14 km from tunnel site in Osaka Bay.
The depth of water was only 5.5-6.3 m. All navigation had to be stopped for nearly 15
hours during placement of the element.
hours during placement of the element.
The element was towed supported by two barges and placed using floating cranes.
Exact position between elements was controlled by divers.
Exact position between elements was controlled by divers.
Rigid concrete filled joint to
abutment structures.
abutment structures.
Continuous steel shell.
Two L-shaped abutment caissons were sunk in place at the river shorelines. The river bed between the abutments was excavated and the element was supported on the abutments, rather than on a prepared foundation, as might normally be the case.