Client : Leighton Contractors
Location : Brisbane, Australia
Year : 2000-2001

Madsen Giersing undertook the design of a temporary bridge in the latter part of 2000 and early 2001, to carry traffic loads at the Normanby intersection in Brisbane. The bridge was necessary to facilitate construction of a tunnel under this busy city intersection as part of the Inner City Bypass project.

To minimise traffic disruption, speed of both installation and removal was paramount. Madsen Giersing produced a modular design in steel with prefabricated deck modules to be placed over welded joists and mounted on pre-installed bored columns. Further, the system was designed to be installed in two separate halves so the traffic flow would not be completely disrupted. The bridge was to serve a secondary function as a propping diaphragm for subsequent tunnel excavation and a system of braces was installed under the deck to tie the system together. This was achieved without disruption to traffic flow.

Again, with a view to minimising disruption to traffic flow, the system including excavation of the roadway was successfully installed over a single and weekend. Some four months later, after completion of the tunnel excavation, the system was removed overnight.

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