Page 11 - TunnelTalk Annual Review 2016

Melbourne metro
and highway proposals
Three teams are shortlisted for construction of Melbourne’s planned A$5.5 billion Western Distributor highway link.
The link is at concept design stage and aims to solve some critical traffic problems by creating a second river crossing, relieving pressure on the West Gate Bridge, and cutting down the number of trucks that service the busy Melbourne Port area from using local roads (Fig 1).
The shortlisted teams are:
• John Holland/CPB Contractors
• Buoygues/Lend Lease
• Salini-Impregilo/Fluor Australia/Lane
Worldwide Infrastructure
Bids from Bechtel Infrastructure Australia and Rizzani De Eccher Australia were received but not shortlisted.
The project is the result of an unsolicited proposal to the Victoria State Government by national toll road operator Transurban. In December 2015, the State Government agreed terms with the privately owned infrastructure provider to develop the proposal through to preliminary design that will run in parallel with local consultation and the planning and environmental review process. The Government has committed Aust$1.44 billion toward the total cost of the project, with future toll income expected to provide the balance.
Project scope includes construction of a twin running tunnel under the residential Yarraville area with a long tunnel or short tunnel solution yet to be decided.
AGovernmentspokesmansaid:“The shortlisted teams will prepare fully costed designs for the project which includes the widening of the West Gate Freeway, the tunnel under Yarraville, a second river crossing, and connections to the port, CityLink and the central business district of Melbourne. In the meantime, a reference design is being developed which will take into account feedback from extensive consultation with local government, local residents, businesses and the freight industry. The construction
contract will be signed by late 2017 and be completed in 2022.”
This highway project for Melbourne comes 18 months after the 4.4 km long East-West Link construction contract was cancelled by an incoming Labour Government. Announcement of the shortlist for the Western Distributor coincides with the first Early Works contract for construction of the all-underground 9km long, Aust$11 billion, Melbourne Metro.
During 2016, three teams were shortlisted for construction of the main running tunnels and stations of the metro project (Fig 2):
• Moving Melbourne Together: Pacific Partnerships/CPB Contractors/Ghella/ Salini-Impregilo/Serco/Macqarie Capital
• Continuum Victoria: Acciona/ Ferrovial Agroman/Honeywell/Downer EDI/ Plenary Origination
• Cross Yarra Partnership: Lendlease Engineering/John Holland/Buoygues/ Capella Capital
Project scope includes TBM excavation
of 8.4km of twin running tunnels, three cut- and-cover stations, two mined stations in the CBD connected by a 600m long roadheader- excavated tunnel, an undercrossing of the Yarra River, and fit out.
Enquiries by TunnelTalk to the project owner Melbourne Metro Rail Authority (MMRA), operating on behalf of the Victoria State Government, reveal that the major underground works will be let as a single Aust$5–6 billion design-build package based ontheAvailabilityPPPprocurementmethod.
Peter DeLuca, for MMRA, said: “An availability-based tunnel and stations public private partnership (PPP) valued between Aust$5 billion and Aust$6 billion includes the design and construction of the twin 9km tunnels and five underground stations, private finance, and the provision of maintenance and other services during the operating term.” This method of procurement has been selected by the owner “due to the size of the tunnel and station package and its complexity and risk profile.”
Peter Kenyon, TunnelTalk “We anticipate awarding the PPP
contract in late 2017, with major works expected to commence in early 2018,” said DeLuca. “Between four and six TBMs, procured by the successful PPP contractor, will be needed to excavate the majority of the rail tunnels.”
In June 2016, MMRA awarded a Aust$324 million early works package which involves the excavation of two deep shafts near the CBD North Station.
John Holland is awarded Aust$324 million for construction of the two deep shafts that will service construction of the central section of the new Melbourne Metro.
The early works package will facilitate construction of the central section of the 9km alignment which will being in early 2017, once environmental approvals are granted.
The two 35m deep shafts will facilitate access for construction of both the CBD North and CBD South mined cavern stations, and the single-tube double-track, roadheader-mined tunnel to connect them.
TBMs will excavate the remainder of the running tunnels.
According to alignment concepts, prepared by the Aurecon/Jacobs/Mott MocDonald (AJM) Joint Venture design team, the main running tunnels will be driven from portals built into cut-and-cover ramps at either end of the 9km alignment.
At its deepest point the tunnel crown will be 40m below the surface, and about 7m deep for the undercrossing of the Yarra River.
In addition to the two cavern stations a further three cut-and-cover stations are to be constructed at Arden, Parkville, and Domain. n
References
• Melbourne kills off road link to revive metro – TunnelTalk, April 2015
• Politics threatens East-West Link in Melbourne – TunnelTalk, October 2014
• Melbourne awards highway mega-project – TunnelTalk, September 2014
• Melbourne contracting model to minimize risk – TunnelTalk, November 2013
• Australia suffers toll concession failures – TunnelTalk, July 2013
From left: Fig 1. The Aust$5.5 billion Western Distributor concept alignment; Fig 2. Alignment and stations of Melbourne Metro
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