IJ crossing North/South Metro Line / The IJ

t126-ij-amsterdam
Amsterdam, Netherlands
HEIGHT: 7.55 m
WIDTH: 12.15 m
TOTAL IMMERSED LENGTH: 425 m (310 m under the IJ-river, 115 m at the northern embankment under land resulting in 10 m of ground cover on top of the immersed tunnel)
DEPTH AT BOTTOM OF STRUCTURE: 21 m
ENVIRONMENTAL CONDITIONS:
Fresh water
Urban environment
Soft to very soft soil conditions (clay, silty sand, sand). The ground conditions at the
southernmost tunnel element are very poor; therefore a ground improvement will be carried out
between combi pile walls that limit the sizes of the immersion trench at the southern
embankment.
FABRICATION METHOD:
Elements were cast in 6 segments of 23.6 m.
t126
Municipality of Amsterdam, Dienst Noord/Zuidlijn
JV Combinatie Strukton/Mergor & Heijmans
Adviesbureau Noord/Zuidlijn (JV of Royal Haskoning and Witteveen+Bos)
141.6m
425m
21m
3
Two tubes with one track each (separation wall constructed after immersion)
7.55m
12.15m
Tunnel element built in the northern approach of the river crossing at the Sixhaven, towed to a
temporary mooring location in the Western Harbor Area in Amsterdam (for 5 years), waiting for
the completion of the Northern Entrance of the metro station Central (which is also the reception
structure for the southernmost tunnel element.
Alignment had to be developed taking into account historic ship locks at the northern
embankment.
Alignment allows for future deepening of the navigation channel to allow bigger cruise ships to
pass.
For economic reasons the immersed tunnel is extended 115 m in the northern embankment
(costs immersed tunnel lower than for very deep cut & cover sections with heavy combi pile
walls, multiple strut layers, underwater concrete & tension piles)
Separation wall between the two tracks is not part of the main tunnel structure.
Elements were cast in 6 segments of 23.6 m.
Fitting out for immersion carried out at
temporary mooring quay in Western
Harbor Area
Fresh water
Urban environment
Soft to very soft soil conditions (clay, silty sand, sand). The ground conditions at the
southernmost tunnel element are very poor; therefore a ground improvement will be carried out
between combi pile walls that limit the sizes of the immersion trench at the southern
embankment.
For placement of the elements crane pontoons and land winches are used. For positioning a
GPS survey system is installed on the access shaft and survey tower.
W9U-I water stop in segment
joint; GINA / Omega seals in
immersion joint
Watertight concrete with artificial cooling of the outer walls during hardening of the concrete,
W9U-I water stop in segment joints, GINA / Omega seals in immersion joint
Sand flow method
1m rock protection
Concrete B35, temporary prestressed, NEN
6720
temporary condition > 1.025 permanent condition > 1.075