Giant concrete beams were suspended in mid-air and carried across the river by crane before they were lowered into position to complete the structure for Perth’s newest bridge over the Swan River.
With each of the 42 beams measuring 31 metres, manoeuvring the beams in position was an intricate process involving the use of two types of crane.
River traffic was closed temporarily to allow a Crawling Crane with a 36-metre reach, to position the beams across the river. The two spans furthest from the foreshore were accessed using this 450 tonne crane. All the beams were laid on temporary jacks until they could be permanently secured.
With the bridge beams in place, the next stage was to cast concrete deck slabs for the roadbed of the bridge. Concrete abutment slabs were also made for either end of the bridge to provide a smooth transition from the road onto the new bridge.
Gordon Williamson, Structures Construction Manager for Macmahon, said: “Completing the structure of the bridge was a significant milestone and we’ll now begin working on the street furniture, such as erecting the safety barriers, pathways and lighting.”
Steel guard rails and a metre high safety barrier will be built on the bridge approaches from both sides, and a pedestrian and cycle pathway will span the length of the new bridge.
At Jane Brook, Continuous Flight Auger or CFA piling was used on the new bridge to speed construction and minimise interruption of the main carriageway. CFA is a non-displacement pile, which is used where fastvibration free installation is required in difficult ground conditions.