Sewer Tunnel

HEIGHT: 4.6 m OD
WIDTH: (circular)
TOTAL IMMERSED LENGTH: 237.3 m
DEPTH AT BOTTOM OF STRUCTURE: 20.3
FABRICATION METHOD:
The five reinforced concrete elements were constructed
in a drydock. Each element was built from three sections
of about 15.25 m in length cast in a vertical position and
connnected by post-tensioning cables.
ENVIRONMENTAL
CONDITIONS:
Constructed across entrance to Durban Harbour
immersed
Durban,
South Africa
s11
Durban Corporation
Christiani & Nielsen (S.A.) (Pty) Ltd
Christiani & Nielsen (S.A.) (Pty) Ltd
2-52.1 m 2-44.8 m 1 - 43.4 m
237.7m
20.3m

Project construction

1960-04-30
5
One tube
4.6m
circular
Three tunnel elements were placed horizont;~lly across the channel and joined to the
two terminal chambers by the remaining elements which were placed at the unusually
steep slope of 40% (2.5 Hor. to 1 Vert.).
The five reinforced concrete elements were constructed
in a drydock. Each element was built from three sections
of about 15.25 m in length cast in a vertical position and
connnected by post-tensioning cables.
Not applicable
Constructed across entrance to Durban Harbour
Light pontoon rig
Double rubber seal, one
soft and one hard.
Not required
Temporary support on concrete rafts on gravel beds. Permanent support on sand fill.
Sand backfill