$3.9b I-64 Hampton Roads Bridge Tunnels expansion delayed 1.5 years

(Satellite)

HRBT = Hampton Roads Bridge Tunnels

"The tunnels [+trestles] are 3.5 miles (5.6 km) long and opened in 1957 (current westbound lanes) and 1976 (eastbound lanes)." [I lost the reference]

The tolls on the 1957 tunnel were removed when the 1976 tunnel was built. [vdot]

WTKR News 3 posted
Hang on, commuters. The HRBT Expansion Project is going to take a bit longer than expected: https://wtkr3.co/43Dyyh1
"HRCP has achieved a multitude of unprecedented milestones to include constructing the 15-acre expansion of the North Island, reassembling the second largest tunnel boring machine in North America, completing the largest continuous concrete pour in VDOT history, and boring and building nearly 90% of the first of the two new tunnels."

Second media in wtkr
$3.9b budget figure was around 0:33.

wtkr
View of south island of HRBT

Current traffic backups sometimes exceed six miles. They plan to go from 2 lanes in each direction to 4 lanes per direction. [2:39 video] In addition to doubling the trestles and tunnels, they have to widen 5 miles of road on land.

Two construction photso from CES. It was their job to keep the project under budget and on schedule.

1

2
[Those circular cells is where the TBM is assembled and launched.]

The start date was Dec 2020 and the expected completion date was Nov 2025. "To complete the project by late 2025, land and tunnel work will occur simultaneously with a Tunnel Boring Machine (TBM) method of Construction. Once completed, twin two-lane bored-tunnels will be built west of the existing eastbound and westbound tunnels. Each tunnel will be approximately forty-five feet [13.7m], creating the second largest tunnel opening for a TBM in North America....HRBT [Hampton Roads Bridge and Tunnel] Expansion is the fourth bored roadway tunnel project in the United States and the first in the state of Virginia." [flatiron]

So construction was expected to take four years. Thus a 1.5-year delay is over a third of the estimated construction time.

flatiron2

HerrenKnech
The current highway was designed for 77,000 vehicles per day, but sees over 100,000. The TBM is "variable Density."

HerrenKnech

An early photo:

VirginiaPlaces

vinci-construction
"The project involves designing and building 5.3km of sea viaducts and new tunnels as well as widening 14.5km of existing roads. As part of the new component, the consortium will excavate two 2.4km-long tunnels between two artificial islands, linked to the mainland by two sea viaducts measuring 1km and 1.9km. The existing component will include demolition, reconstruction and widening of 14.5km of road [my emphasis, one reason the project is so expensive is that they are evidently replacing a lot of the existing trestles.], with two additional traffic lanes being created in each direction....In terms of the tunnel excavation, the clay soils found around the artificial islands entail ground reinforcement issues. Given the various soil conditions, the use of a variable density TBM with a convertible cutting head enables tools to be switched under atmospheric pressure, avoids the need for divers and reduces the risks involved."

"The twin tunnels on the Hampton Roads Bridge-Tunnel are each 7,479 feet [2.3km, 1.4miles] long, and the roadway is 108 feet [33m] below sea level at the lowest point....The Hampton Roads tunnels were built by the immersed sunken tube method, comprised of shipyard-built prefabricated tunnel elements each about 300 feet [91m] long, placed by lay-barges and joined together in a trench dredged in the bottom of the harbor, and backfilled over with earth." [RoadsToTheFuture]

One of the reasons given for the 1.5-year delay was the use of "new technology." This made me wonder what the old technology was. Now I know the new technology is TBM, and the old was cut-and-cover. I still don't know what problems they encountered with the new technology.

The new tunnels are significantly deeper than the old ones to bore through more stable soils (clays?).

VirginiaPlaces_hrbt

hrbtexpansion_tunnel
"The TBM launched from the South Island (Norfolk side) in April 2023, and tunnel at a rate of about 50 feet per day."
"The HRBT Expansion Project held the Tunnel Boring Machine (TBM) Naming Contest in the fall of 2020. The contest was open to middle school students in Hampton Roads. First place winner of the contest was Saint Gregory the Great Catholic High School in Virginia Beach with the name, “Mary the TBM” in honor of Mary Jackson of Hampton, VA – mathematician and aerospace engineer at NASA, noted for her pioneering role of an African American woman in the field of science and engineering, and her crucial contributions to the NASA Space Program. The winning name, “Mary the TBM”, will be printed on the TBM that will bore the new twin tunnels at the Hampton Roads Bridge Tunnel."

hdrinc
[If you feel the need to be told that this is a complex design, then this is the reference for you.]

USACE_structural, p16 via USACE

USACE_permit, p25 via USACE

Apr 2024: the first tunnel is done.

2:19 video
[They called it the third bored tunnel in the US. [1:16] I'm surprised it is so few. They called it the largest "of its kind" in the world. [1:56] I wonder what "kind" was used in Seattle. I thought it used a TBM that had a larger diameter.]

0:30 video