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Bridge cantilever construction - applications

This type of construction has been used in a large number of bridges around the world. Spans of up to 70 m have been built with a constant cross section, but a variable depth cross section is required for longer spans.

Advantages:
●There is no need for false work to support the deck during casting in the spanned area.
●The deck is cast in small segments hence improving concrete quality control and formwork.
●Work is repetitive resulting in manpower efficiency with time.
●Several spans could be started at the same time hence reducing construction time

Disadvantages:
●Maximum hogging moment due to dead load is experienced during construction.
●Special gantries or hanging formworks are required.
●Time dependent and stage construction influence the interface geometry of the segments.

Further information:
For further information see Concrete Society Current Practice Sheet 153, Balanced cantilever bridges, published in CONCRETE in November 2007. Copies of the Current Practice Sheet may be downloaded from the Members’ Area of the Concrete Society web site or from the Concrete Bridge Development Group (CBDG) website.
 

Acknowledgement: Gifford Consulting

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