Syphon under the Nile
HEIGHT: 4.35 m
WIDTH: 3.75 m
TOTAL IMMERSED LENGTH: 464 m
DEPTH AT BOTI'OM OF STRUCTURE: 20.9 m at flood
FABRICATION METHOD:
Elements were vertically cast, then turned, lined up, and
posttensioned. Special runners picked them up. These
runners were used to launch the element sideways into
the water.
ENVIRONMENTAL CONDITIONS:
Schedule had to fit low water during January and flood conditions during August
through October. Launching could not be done during low water. Dredging and placing
could not be accomplished during flood conditions. Slipways were constructed at site.
WIDTH: 3.75 m
TOTAL IMMERSED LENGTH: 464 m
DEPTH AT BOTI'OM OF STRUCTURE: 20.9 m at flood
FABRICATION METHOD:
Elements were vertically cast, then turned, lined up, and
posttensioned. Special runners picked them up. These
runners were used to launch the element sideways into
the water.
ENVIRONMENTAL CONDITIONS:
Schedule had to fit low water during January and flood conditions during August
through October. Launching could not be done during low water. Dredging and placing
could not be accomplished during flood conditions. Slipways were constructed at site.
Cairo,
Egypt
Municipality of Cairo
Hochtief, AG Volume
Hochtief, AG
40.5-56.8m
464m
20.9m
Project construction
1964-04-30
9
One tube; carries two 1.20 m dia sewer force mains.
4.35m
3.75m
Vertically cast segmental construction. Interior pipes install~l prior to installing end
bulkheads. 5 m segments weighed about 40 t. Up to 11 segments were posttensioned
into a tunnel element.
bulkheads. 5 m segments weighed about 40 t. Up to 11 segments were posttensioned
into a tunnel element.
Elements were vertically cast, then turned, lined up, and
posttensioned. Special runners picked them up. These
runners were used to launch the element sideways into
the water.
posttensioned. Special runners picked them up. These
runners were used to launch the element sideways into
the water.
Internal force mains were
installed prior to installation
of the dam plates.
installed prior to installation
of the dam plates.
Schedule had to fit low water during January and flood conditions during August
through October. Launching could not be done during low water. Dredging and placing
could not be accomplished during flood conditions. Slipways were constructed at site.
through October. Launching could not be done during low water. Dredging and placing
could not be accomplished during flood conditions. Slipways were constructed at site.
Catamaran pontoon assembly at the one end and a jack-up platform at the other, both
equipped with lowering winches were used. Ballasting was done by partly filling the
sewer lines installed in the elements. Alignment was done by using survey columns.
equipped with lowering winches were used. Ballasting was done by partly filling the
sewer lines installed in the elements. Alignment was done by using survey columns.
Tremie concrete joint. Interior
welded steel liner
plates welded in place after
elements were accessed
from inside.
welded steel liner
plates welded in place after
elements were accessed
from inside.
Vertically cast using high density concrete. Steel joint closures.
Saddle blocks were cast in place against the bottom of the trench using tremie concrete.
Forms were attached to the elements prior to placement and sand bags were
used to seal around them. Used floating batch plant.
Forms were attached to the elements prior to placement and sand bags were
used to seal around them. Used floating batch plant.
2 m of quarry stone over one meter of sand backfill above tunnel.