Shani Wallis, TunnelTalk
WSDOT Contract Award Manager David Mariman (left) and Program Administrator Ron Paananen open the bids By Seattle Times
- Seattle Tunnel Partners, the consortium of Dragados-USA, HNTB Corp and with US contractor Tutor-Perini of California, has emerged as the best value proposer for the Alaskan Way highway replacement tunnel in Seattle, presenting a bid to complete the 9,100ft (2.7km) tunnel with a massive 58ft (17.6m) diameter closed-face TBM and have it open for service nearly a full year earlier than the contractual due date.
- At a public bid opening on Thursday 9 December, the financial proposals from two competing bidders for building the mega-TBM excavated underground highway were announced and the value of credits assigned to each proposal through the weeks of technical evaluation subtracted from the bid estimate to reveal the apparent best value proposal.
- The bid opened from Seattle Tunnel Partners presented a slightly higher base cost than its one rival, but offers to build the tunnel almost a year earlier than the client's due date and at a larger diameter than the 54ft (16m) minimum gave it almost twice the value of technical credits to bring its bid below that presented by the Seattle Tunneling Group, comprising S.A. Healy, FCC Construction of Spain and designers S.A. Parsons Transportation Group and Halcrow.
- Seattle Tunnel Partners presented a base bid of $1.09 billion and after subtracting $72 million in technical credits, the resulting $1.02 billion price was lower than the rival. The principal credits were earned by the group's proposal to complete the tunnel by late December 2015. This is set against an official opening date of 1 November 2016 with a $50,000/day credit or each day saved towards a targeted opening date of 31 December 2015. In its design-build proposal, the group has also added an extra 4ft to the TBM diameter for a 58ft (17.6m) diameter TBM drive that will provide an 8ft shoulder lane on each traffic deck as opposed to the 6ft shoulders of the owner's contract design.
- Proposals for the estimated $1.96-$2.1 billion design-build tunnel contract were submitted on the 28 October due date. Since then, the technical submission of the two-part proposals have been considered by the project's management team and its Program Management and Advisory Consultant, Hatch Mott MacDonald, to identify the technical credits for undertakings in excess of the requirements contained in an already high level of technical specifications. These benefits to the owner were given a dollar value and that was subtracted from the financial proposals that were opened yesterday (9 Dec 2010). Bid evaluation also included close scrutiny of methods proposed for monitoring movement of structures over passage of the TBM beneath the downtown city centre and of controlling volume loss settlement. The huge 58ft (17.6m) diameter machine is specified as an EPB or slurry closed-face TBM system with the final decision to be made by the winning construction team. Herrenknecht and a team of Robbins with NFM of France and two manufacturers known to be competing to win the order for the massive tunnelling machine.
- Opening of the financial proposal yesterday (Thursday 9 December) is earlier than the project's planned financial bid opening date of 23 December and all is confirmed on track for a contract to be awarded early in the New Year following a 10 day period in which any challenges can be raised and once all required contract procedures have been met.
Mega-bored tunnel will replace waterfront viaduct
- Plans for replacing the 57-year old elevated highway across Seattle's foreshore started in 2001 when a heavy earthquake left the double-deck concrete structure severely damaged. Funding for a much larger $4.24 billion capital investment, that includes rebuilding the earthquake damaged seawall as well as replacing the elevated viaduct, is divided between the State of Washington as owner of the SR-99 highway, the City of Seattle, which owns the land on which the viaduct stands and the adjacent seawall, plus King County, that runs public transit bus services on the highway, and the Port of Seattle that will benefit by the easier accesses to its waterfront facilities offered by the new highway configuration. To the project the State has pledged a maximum $2.8 billion while the City has allocated $927 million, the County $190 million, and the Port $300 million. The $1.96 billion 60%-reliability estimate includes for the tunnel excavation contract includes design, right of way, construction management, and a $415 million contingency against risk mitigation and inflation.
- With the project fully funded and the existing viaduct accepted as being a high-risk element in any future earthquake in the region, there is little prospect of the project meeting the same cancellation fate as the Access to the Region's Core rail tunnel project under the Hudson River into Manhatten in New Jersey. There are hurdles however to overcome. First, there is strong opposition to the project by Seattle's Mayor Mike McGinn who is fiercely against the exposure of the City's taxpayers to potential cost over runs above the State's capped allocation. This is in contrast to the Mayor's City Council, which is eight to one in favor of the tunnel project and the full support of the project by the State Governor, Chris Gregoire.
- In addition environmentalists argue that investment should be spent on expanding Seattle's public transit rail and bus systems and on improving the city's I-5 highway to reduce carbon emissions. Proponents and supporters of the tunnel emphasis the advantage of placing the SR-99 highway traffic underground to present a quieter waterfront that will be rejoined to the city when the elevated viaduct barrier is taken down.
- A second hurdle ahead of taking the project into construction is approval of the final environmental impact statement (EIS) by the Federal Government, which will not be in hand until August next year. Advancing the bidding process months ahead of that necessary approval provided a year's head start on the project. Planned award of the contract in January will allow the design-build group to proceed with work that is 'project neutral' including the substantial design work required ahead of building the tunnel. A second notice to proceed will be issued once the final EIS and ROD (Record of Decision) is secured.
Alaskan Way mega-project procurement - TunnelTalk, October 2010
ARC cancellation hits industry hard - TunnelTalk, Nov 2010
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