Gateway Upgrade

Reinforced Earth® Walls & Abutments
TerraPlus® & TerraTilt®

Location:
Brisbane, QLD, Australia
Owner:
Main Roads, QLD
Consultants:
Maunsell Australia Pty Ltd/ SMECJV
Contractor:
Leighton Abigroup JV
Construction:
South Mid 2007, North Early 2008

The Gateway motorway is hailed as the centrepiece of the Australian Trade Coast (incorporating Brisbane airport and port) and surrounding industries.

When the Gateway Bridge opened in 1986, it carried 12,500 vehicles/day. Just over 20 years later the Gateway Motorway is now exceeding capacity, carrying more than 100,000 vehicles/day.

The result: A $1.88 billion Gateway Upgrade Project - the largest bridge and road project in Queensland’s history. It involves

  • Construction of a second Gateway Bridge.
  • Upgrade of 20 kilometres of the Gateway Motorway from Mt Gravatt-Capalaba Road in the south to Nudgee Road in the north.
  • Construction of a new Gateway Motorway deviation, providing a more direct route north of the river and better access to Brisbane Airport.

Duplicating one of Brisbane's most recognisable structures, the Gateway Bridge was never going to be easy. That's why the winning contractor (Leighton Abigroup Joint Venture, LAJV) turned to The Reinforced Earth Company (RECO) to deliver over 15000 m² of Reinforced Earth® walls on the Gateway Upgrade Project (GUP).

There were three major challenges for RECO to overcome on the GUP:

  1. The request for a unique facing pattern on some of the Reinforced Earth® walls.
  2. Poor foundation conditions.
  3. A bridge abutment upgrade adjacent to a heavily trafficked suburban railway.

The GUP was broken into two manageable sections North of the bridge and South of the bridge, with each section having approximately equal quantities of walls yet very different engineering, architectural and programming requirements.

LAJV's southern section first approached RECO mid 2007 to supply 5-6 structures in a very short time frame as traffic needed to be transferred onto the new section in time for the Christmas traffic of 2007. Despite the compressed program the client also insisted that no shortcuts were taken, therefore all facets of RECO's supply, the design, manufacture and delivery needed to run concurrently. This was successfully achieved with the commitment of all aspects of the company working seamlessly together.

“One of the biggest challenges lay in the detailing and manufacturing of the numerous

unique patterns on the TerraPlus® facing panels”, comments James Bye, RECO’s Operations Manager.

In order to achieve the unique detailing required on the panel facings, RECO worked closely with the project’s architect, EDAW, and with the help of it’s mould fabricator, F&E Moulds, has met the challenge with distinction. “Flow”, “Strata” and “Port” themes were developed for the wall panels on the project, with the latter to reflect the industrial relation with the port nearby.

The panels were precast locally to the project at RECO’s Wacol production plant, south of Brisbane.

In the design office, Chris Lawson’s (RECO Engineering Manager) challenge was to deliver designs to compliment the geotechnical engineer’s extensive use of piling foundations and bridge piles to overcome poor foundation conditions.

“We were able to accommodate the presence of the piles within the Reinforced Earth block with the use of many individually detailed facing panels which allowed horizontal and vertical splaying of soil reinforcing strips to accommodate these large diameter piles”, comments Mr Lawson.

Another major challenge related to the close proximity of a bridge abutment upgrade to a heavily trafficked suburban railway. In order to quickly create a safe working area RECO’s TerraTilt® system was selected as the most appropriate solution. This was the first time TerraTilt® has been used on the east coast of Australia. TerraTilt had previously only been used in WA where good ground conditions and quality backfill make it a suitable solution.

TerraTilt® comprises precast concrete full height facing panels and steel reinforcing strips which are attached to the back of the panels, and buried in the compacted fill to create the abutment around the columns. Construction of the 442m² wall using 8.8m high full height panels took place on a very tight construction timeline. The railway line was shut down over the weekend and construction continued round the clock to minimize impact on rail traffic.

  • At 15 000m², GUP is one of RECO Australia’s largest public infrastructure contracts.
  • Unique TerraPlus® finish.
  • Many individually detailed facing panels allow horizontal and vertical splaying of soil reinforcing strips to accommodate large diameter piles and overcome poor foundation conditions.
  • First use of TerraTilt® full height panels on the east coast of Australia.

Project Specifications

System
TerraPlus® & TerraTilt®
Structure
Retaining Wall
Area
7663m² (North) 7416m² (South)
Height
12.5m
Design Load
25kPa
Design Life
100 years
Finish
Plain, Flow, Strata, and Port Panels

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Great Northern Highway Realignment

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