No tax dollars are being used for the project.ĬBBT expects to add a parallel tunnel at the Chesapeake Channel, but not for another 20 years, Holland said. The district is comprised of six cities: Virginia Beach, Norfolk, Portsmouth, Chesapeake, Hampton, Newport News, and the two Eastern Shore counties of Northampton and Accomack.ĬBBT plans to pay for the parallel tunnel through a variety of means, including the sale of revenue bonds, the district’s general fund, and several loans, including a $50 million loan from the Virginia Transportation Infrastructure Bank and a $321 million Transportation Infrastructure Finance and Innovation Act loan, Holland said. The CBBT District, governed by the CBBT Commission, was created as a political subdivision by the Commonwealth of Virginia in 1954. The tunnels are shut down during an accident, or a crossing by a wide-load vehicle or a truck with hazardous materials, causing further delays.īesides improving traffic flow, the new tunnel will increase safety, offering additional lanes during routine tunnel maintenance or as an alternate route during an accident or other closure. Because traffic is funneled back to a two-lane tunnel for the underwater crossing, delays are common, he said. “Not a huge number compared to other tunnels,” he said, “but that number is kind of misleading.”ĭuring the peak summer season, daily crossings increase to 25,000 vehicles. On an annual basis, the Chesapeake Bay Bridge-Tunnel sees 4 million vehicle crossings, Crist said. The project has an an anticipated total cost of $810 million. The CBBT Commission broke ground in September 2017 to build its new tunnel. The 10 other tunnels that have been constructed in Hampton Roads have all been completed using the immersed tube tunnel method. The Channel Tunnel, or “Chunnel,” from the U.K. TBM technology is typically used for hard rock tunneling. The real change over the past 15 years is the ability to do TBM in soft, silty clay material underwater.” “Tunnel boring machines have been around for a long time,” said Mike Crist, CBBT’s deputy executive director of infrastructure. The entire project is expected to be complete by fall 2022. Once the tunnel liner is completed, then the final roadway, lighting and mechanical systems will be installed. After the TBM reaches Island 2, it will be disassembled and removed. At the same time, about 9,000 precast concrete tunnel segments will be delivered to the TBM, which will precisely place the segments as it progresses. It is expected to bore 50 ft a day.Īs the TBM excavates, an estimated total of 500,000 cu yd of soil will be brought back to Island 1 for removal. The 300-ft-long TBM will use a 42-ft rotating head to cut into the sandy soil. The TBM is expected to be delivered by late 2018, with boring construction beginning in spring 2019, Banas said. ![]() Those pieces will be assembled at the bottom of an excavated pit at Island 1, where construction has started. ![]() ![]() The boring machine is currently being built and will be delivered to the site in several large pieces. LLC submitted the lowest bid of $756 million using the bored tunnel method. But it’s a vital link for the region that it serves.”ĭragados USA Inc. It’s at the mouth of the ocean and out on the water. “This type of construction is not as common in soft ground, and is only recently coming into use in the U.S.,” said Ryan Banas, P.E., CCM, project manager at HNTB, who serves as the construction management consultant. The project has an anticipated total cost of $810 million, according to CBBT Executive Director Jeff Holland. Unlike the original tunnel, which was constructed as an immersed tube tunnel, the parallel line is using a tunnel-boring machine (TBM). The Chesapeake Bay Bridge and Tunnel Commission (CBBT) broke ground in September 2017 to build its new tunnel. Now, more than a half century after the original “engineering wonder,” a project to build a parallel tunnel in the Thimble Shoal Channel will continue that tradition of modern marvel and innovation. In the 1990s, parallel bridges were added along the crossing, which are connected by two nearly 1-mile-long two-lane tunnels beneath the Thimble Shoal and the Chesapeake navigation channels. The 17.6-mile vehicular toll crossing of the lower Chesapeake Bay is a north-south highway and provides the only direct link between Hampton Roads and Virginia’s Eastern Shore. When it opened in 1964, the Chesapeake Bay Bridge-Tunnel was considered one of the seven engineering wonders of the modern world-incorporating two-lane bridges and tunnels for vehicular traffic to get from southern Virginia to the Delmarva Peninsula in Delaware.
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