Mount Henry Bridge
Encyclopedia
The Mount Henry Bridge carries the Kwinana Freeway
and Mandurah railway line over the Canning River
in Perth, Western Australia
, approximately 10 kilometres (6.2 mi) south of the Perth central business district. At 660 metres (2,165.4 ft) long, it is the longest road bridge in Western Australia
. It spans the river between the Mount Henry Peninsula
and the suburb of Brentwood
.
The bridge was constructed as part of the extension of the Kwinana Freeway carried out in the late 1970s and early 1980s. The bridge was opened in 1982. The construction contractor was Clough, and the project manager for Main Roads WA was Geoff Smith.
Between 2004 and 2006, the Mount Henry Bridge was widened and strengthened to accommodate the tracks of the Perth Southern Suburbs Railway. The widening was carried out by adding an independent structure, which overlaps the original bridge.
s) carrying traffic, and cantilevers at the bottom of the box carrying pedestrian / cycle paths. The bridge was constructed segmentally, using a balanced caltilever construction method. The original bridge carried three lanes of traffic in each direction, with two pedestrian / cycle paths on cantilevers at the lower lever.
Because of the aesthetic requirements, load limitations and limited site space at the approaches, the new bridge overlaps the original in cross section. The upper east side cantilever sits above the upper west side cantilever of the original structure, giving a total effective deck width of 40 metres (131.2 ft). The foundations of the new bridge are independent of the original, with each pier comprising two columns tapering from bottom to top.
The new bridge was constructed by incremental launching. Contractors were Leighton Constructions. The design team comprised Wyche Consultants, GHD and Coffey Geosciences.
Kwinana Freeway
The Kwinana Freeway is a major arterial road in Perth, Western Australia, linking Perth with the southern suburbs and then further on towards Mandurah, a distance of . It has a speed limit of , except in central Perth and south of Lakes Road . Like all Western Australian freeways, the minimum...
and Mandurah railway line over the Canning River
Canning River (Western Australia)
The Canning River is a major tributary of the Swan River in south western Western Australia.-Source and route:With headwaters on the Darling Scarp, the Canning meanders through suburbs of Perth on the Swan Coastal Plain, including Cannington, Thornlie, Riverton, Shelley, Rossmoyne and Mount...
in Perth, Western Australia
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
, approximately 10 kilometres (6.2 mi) south of the Perth central business district. At 660 metres (2,165.4 ft) long, it is the longest road bridge in Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. It spans the river between the Mount Henry Peninsula
Mount Henry Peninsula
Mount Henry Peninsula is a land feature and reserve located 11 km south of Perth, Western Australia, on the north bank of the Canning River near the Mount Henry Bridge in Salter Point, Western Australia. It covers 11.9 hectares, and includes both Banksia attenuata and Banksia menziesii woodland...
and the suburb of Brentwood
Brentwood, Western Australia
Brentwood is a suburb of Perth, Western Australia, located within the City of Melville.It is named for Brentwood, an English town near London which was the birthplace of John Bateman, a pioneer settler in the area....
.
History
Between 2004 and 2006, the Mount Henry Bridge was widened and strengthened to accommodate the tracks of the Perth Southern Suburbs Railway. The widening was carried out by adding an independent structure, which overlaps the original bridge.
Structural details
The original bridge is of post-tensioned concrete. It has nine spans with a total length of 660 metres (2,165.4 ft). The deck width is 28.8 metres (94.5 ft). In cross section it is a double box-section, with the upper deck (including cantileverCantilever
A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is resisted by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.This is in...
s) carrying traffic, and cantilevers at the bottom of the box carrying pedestrian / cycle paths. The bridge was constructed segmentally, using a balanced caltilever construction method. The original bridge carried three lanes of traffic in each direction, with two pedestrian / cycle paths on cantilevers at the lower lever.
Widening and strengthening
To accommodate the new Southern Suburbs Railway (now the Mandurah railway line), the bridge was widened and strengthened between 2004 and 2006. Under the new arrangement, the original bridge carries three southbound traffic lanes and the two railway tracks. The new structure carries the three northbound traffic lanes.Because of the aesthetic requirements, load limitations and limited site space at the approaches, the new bridge overlaps the original in cross section. The upper east side cantilever sits above the upper west side cantilever of the original structure, giving a total effective deck width of 40 metres (131.2 ft). The foundations of the new bridge are independent of the original, with each pier comprising two columns tapering from bottom to top.
The new bridge was constructed by incremental launching. Contractors were Leighton Constructions. The design team comprised Wyche Consultants, GHD and Coffey Geosciences.