Hampton Roads crossing plans revitalized in USA 20 Jul 2017

A request for qualifiers (RFQs) for construction of the US$3.3 billion Hampton Roads Bridge-Tunnel expansion project is scheduled for Fall this year (2017) following issue of a formal record of decision (ROD) by the US Federal Highways Authority.

From a number of proposals, Corridors 8 and 9 of the Alternative A are selected as preferred options to relieve traffic congestion in and around the Hampton-Norfolk-Portsmouth triangle and in the state of Virginia (Fig 1).

Existing configuration of the Hampton Roads Bridge-Tunnel Bay crossing

As part of the project, the Interstate I-64 highway across the mouth of Chesapeake Bay between Hampton and Norfolk will be widened from four to six lanes with a third trestle bridge increasing the crossing from the Hampton side to North Island and from the Norfolk side to South Island, and a new 7,500ft-long (2.2km) tunnel between enlarged North and South Islands to provide relief for the existing pair of two-lane immersed tube tunnels.

According to a national study carried out in 2011, the existing two-lane crossings are among the top 100 most congested highways in the USA. When the first two-lane immersed tube tunnel was opened to traffic in November 1957, an average 6,000 vehicles used the crossing each day. A second tube added in 1976 increased design capacity to 77,000 vehicles per day, but today the bridge-tunnel crossing is handling traffic volumes of up to 100,000 vehicles a day.

Fig 1. Federal ROD favored option to widen existing bridges and add a new parallel tunnel

A Virginia Department of Transportation (VDoT) spokesman declined to answer questions at this stage of the project, but confirmed to TunnelTalk that the planned new project will provide three extra traffic lanes. This is one lane less than originally proposed in the 2008 feasibility study.

The decision to proceed with the project brings to a conclusion a period of 16 years that has seen a 2001 Federal ROD in support of a reduced-scope project, numerous alignment and technical studies, a formal crossing study in 2008, three unsolicited construction proposals in 2010/11, and the termination of an earlier construction procurement process in 2014.

The first unsolicited conceptual proposal was submitted to the VDoT in September 2010 by the Skanska/ Kiewit/ Weeks Marine (Hampton Roads Crossings) JV, with Parsons Brinckerhoff as lead designer. After accepting the proposal in October 2010, VDoT called for competing proposals and in February 2011, a second conceptual proposal was received from the Cintra Infraestructuras SA/ Ferrovial Agroman JV. A third proposal received from the ACS/ Dragados USA/ Flatiron JV (Hampton Roads Mobility Group), with Moffatt & Nicol as lead design engineer, and Arcadis as tunnel design engineer, proposed to double tunnel capacity by adding a four-lane westbound immersed tube tunnel, and dedicating the existing tubes to eastbound traffic only (Fig 2). This would also have had the benefit of facilitating the westbound movement of overheight trucks across the Bridge-Tunnel. Such vehicles are currently unable to use the crossing.

In 2014 VDoT wrote to all three teams to cancel the project based on legislation to assess “multiple opportunities for transportation improvements throughout the Hampton Roads region”.

Fig 2. The ACS/ Dragados/ Flatiron 2011 conceptual proposal

Following amendments to the original environmental impact study, and issue of a revised ROD to supersede the original one of 2001, owner VDoT hosted a contractor’s conference in April this year (2017) to test interest in the project. This atracted 271 delegates representing top American and international contractors and engineering design consultancies. Of these, 16 major US and international contractors and financiers responded to the owner’s request for information (RFI) and held discussions with VDoT concerning their construction procurement preferences.

The contractors that responded to the RFI included the three teams that made unsolicited proposals in 2010/11 – ACS/Dragados, Cintra/Ferrovial Agroman, and Skanska/Kiewit/Weeks Marine – and companies Bechtel, Condotte America, FCC Construction, Fluor, John Laing, Lane Construction, Macquarie, Transurban and Vinci.

New Midtown immersed tube tunnel under Elizabeth River

One of the most interesting responses to the RFI comes from the Cintra/Ferrovial Agroman JV, which suggested that a 4+4 lane design, rather than the current 3+3 lane proposal, might offer better long-term value. To this end, its proposal includes an option to construct two new 4-lane tunnels and decommission of the existing and aging, 2 x 2-lane tunnels which both feature below-standard vertical clearances and narrow emergency lanes.

Although no decision has yet been made on the method of tunnel construction, it is likely to be an immersed tube tunnel to match the existing tubes, which are circular profile steel immersed tunnels (see below). A feasibility study carried out in 2008 concluded that it was not likely that a TBM could be used to excavate the new tunnel on account of the “looseness” of the geology in the upper layers of a bored tunnel alignment. If a TBM were to be used, the new tunnel would have to be aligned deeper to provide adequate cover and would result in a “significantly longer tunnel”.

Thimble Shoals crossing of Chesapeake Bay Bridge-Tunnel

Given these geological limitations, the 2008 study recommended a concrete rectangular-profile immersed tunnel running 250ft outside the alignment of the existing eastbound tunnel, a solution which would require the widening of the existing man-made North and South Islands. The risk of damage to the two existing tunnels by running the new tunnel between them was considered too high.

According to VDoT’s current project schedule, the final decision between the design-build procurement method, or the concessionary design-build-finance-operate-maintain or design-build-operate-maintain (DBOM) methods, will be made later in this Summer. A construction shortlist is due to be announced in Spring next year (2018), followed by a request for proposals in Summer 2018 ahead of a planned contract award in Summer 2019. Construction is anticipated to take five years, with the expanded Bridge-Tunnel opening in 2024.

This will be the third major highway tunnel project in Virginia in recent years joining the US$1.46 billion 1,700m long immersed tube Midtown Tunnel across of the Elizabeth River between Norfolk and Portsmouth, which opened fully to traffic in August 2016 to relieve the over-capacity Downtown Tunnels, and the 1,740m long parallel Thimble Shoals TBM tunnel for the Chesapeake Bay Bridge-Tunnel crossing awarded to the Dragados/Schiavone JV in July 2016 for US$755 million.