Hemspoor Tunnel
HEIGHT: 8.70 m
WIDTH: 21.43 m
TOTAL IMMERSED LENGTH: 1,475 m
DEPTH AT BOTTOM OF STRUCTURE: 26 m
ENVIRONMENTAL CONDITIONS: Virtually no current in the canal.
FABRICATION METHOD: Tunnel elements built in drydock formed by extending the existing docks used for the Coen and Ij tunnels. Tow 6 km. long.
WIDTH: 21.43 m
TOTAL IMMERSED LENGTH: 1,475 m
DEPTH AT BOTTOM OF STRUCTURE: 26 m
ENVIRONMENTAL CONDITIONS: Virtually no current in the canal.
FABRICATION METHOD: Tunnel elements built in drydock formed by extending the existing docks used for the Coen and Ij tunnels. Tow 6 km. long.
Under North Sea Canal (?),
Netherlands
Dutch Railways.
Hemspoor joint venture: Royal Bos Kalis Westminster Group N.V. and Stevin Groep N.V.
Locks and Weirs Division of the National Public Works.
4 - 268 m 3 - 134 m
1,475m
26m
Project construction
1980-04-30
7
Three tubes; one track each.
8.70m
21.43m
Three-track tunnel; middle track is used for wide goods trains. Four straight elements
were constructed twice as long (268 m) as the remaining three curved elements (134
m). These long elements displaced a record 50,000 tonnes. This was possible because
there is no current in the North Sea Canal and there was sufficient room to manuever.
The sections of each element were temporarily tied together with plain reinforcing steel
instead of prestressing rods. As in other tunnels, these ties were cut after the element
was in its final condition.
were constructed twice as long (268 m) as the remaining three curved elements (134
m). These long elements displaced a record 50,000 tonnes. This was possible because
there is no current in the North Sea Canal and there was sufficient room to manuever.
The sections of each element were temporarily tied together with plain reinforcing steel
instead of prestressing rods. As in other tunnels, these ties were cut after the element
was in its final condition.
Tunnel elements built in drydock formed by extending the
existing docks used for the Coen and Ij tunnels. Tow 6
km. long.
existing docks used for the Coen and Ij tunnels. Tow 6
km. long.
Virtually no current in the canal.
Transverse placement barges on top of element. Survey towers were not used, but an
access shaft was provided on each element. The center between immersion load lines
was used for positioning. Proper register between elements was obtained with a sensor
operated between the bulkheads. Levelling was done internally.
access shaft was provided on each element. The center between immersion load lines
was used for positioning. Proper register between elements was obtained with a sensor
operated between the bulkheads. Levelling was done internally.
Gina joints. Last joint was made using gasketted plates to
permit joint dewatering.
permit joint dewatering.
Intermediate joints at 22.35 m intervals were provided to reduce shrinkage cracking and
accommodate settlements. The roof was protected with a concrete slab placed just prior
to sinking the tube. This reduced the freeboard to only 5 cm.
accommodate settlements. The roof was protected with a concrete slab placed just prior
to sinking the tube. This reduced the freeboard to only 5 cm.
The sand-flow method was different, in that sand slurry was pumped into the individual
elements through hoses attached by divers.
elements through hoses attached by divers.
Reinforced