Chalumna Bridge

Type: Double Curvature, Pre-Stressed Concrete Bridge
Construction Date: 1994 - 1996
Location: 40km south-west of East London, South Africa
S 33.166277° E 27.565702°
Chalumna Bridge is situated 40km south-west of East London and at its time of construction was considered an engineering marvel in South Africa. The construction of this bridge saw the pre-stressing of concrete technique to be implemented.

Furthermore, the deck was fully externally pre-stressed and launched on a double curvature. According to specialists, this method of construction resulted in a bridge that should be more durable and requires less maintenance in future.

Chalumna Bridge Instrumentation consists of the following:
  • Vibrating Wire Strain Gauge in the deck and sides, measuring concrete and re-enforcing strain.
  • Vibrating Wire Rebar Strain meter in the base, measuring strain on the reinforcing inside the concrete.
  • Vibrating Wire Surface Mounted Strain Gauges in the sides, measuring external concrete strain.
  • Vibrating Wire Load Cell measuring the pre-stressed steel cables.

Instruments installed in Bridge are intended to monitor:
  • Stresses and strain of the internal reinforcing and concrete;
  • Stresses and strain of the external concrete;
  • Total tension of the pre-stressed cables;
  • Stresses and strain of the horizontal reinforcing.

Installed Instruments Specification:
Concrete Strain Gauge (Piers, deck installation)
Geokon Vibrating Wire Model 4210
Rebar Strain Meter (Piers, deck installation)
Geokon Vibrating Wire Model 4911
Load Cell (Prestressed steel cables)
Geokon Load Cells (Vibrating Wire) Model 4900

Designers: N/A

Consulting Engineers: Steward Scott Incorporated (SSI)

Contractors: Group 5

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