Niigata Port Road Tunnel
HEIGHT: 7.64 m
WIDTH: 28.6 m
TOTAL IMMERSED LENGTH: 850 m
DEPTH AT BOTTOM OF STRUCTURE: -23 m
ENVIRONMENTAL CONDITIONS:
At the mouth of a river with high velocity currents. Heavy snows during the winter
affected land operations.
FABRICATION METHOD:
Fabricated in dry dock.
WIDTH: 28.6 m
TOTAL IMMERSED LENGTH: 850 m
DEPTH AT BOTTOM OF STRUCTURE: -23 m
ENVIRONMENTAL CONDITIONS:
At the mouth of a river with high velocity currents. Heavy snows during the winter
affected land operations.
FABRICATION METHOD:
Fabricated in dry dock.
Niigata,
Japan
105-107.5m
850m
23m
Project construction
8
Two tubes; two lanes each tube
7.64m
28.6m
Constructed in earthquake zone. Ambient ground is soft sand with potential for
liquefaction. Measures were taken to prevent liquefaction.
liquefaction. Measures were taken to prevent liquefaction.
Fabricated in dry dock.
At the mouth of a river with high velocity currents. Heavy snows during the winter
affected land operations.
affected land operations.
Element supported by pontoons. Ballasting by internal water tanks.
Flexible joint used Ginatype
gasket and posttensioned
cables across
joint.
gasket and posttensioned
cables across
joint.
Steel plate around the element with upper slab covered with rubberized waterproofing
layer.
layer.
Non-segregating cement grout was pumped under the elements.
1.5 m of backfill with concrete layer on top of element.