2. What Is The Big Dig?
OLD CENTRAL ARTERY (I-
93)
NEW CENTRAL ARTERY (I-93)
6 Lane Elevated Artery 8-10 Lane State of the Art
Underground Highway
“Largest, most complex, and technologically challenging highway
project in the history of the United States”
-Solution To Boston’s Traffic Problem
-Reconnect Waterfront Towns To Downtown
3. BRIDGES TUNNELS
Leonard P. Zakim Bunker Hill Ted Williams Tunnel
Leverett Circle Connector Thomas P. O’Neill Jr.
Widest Cable-Stayed Bridge
4. WHY WE CHOSE “THE BIG DIG”
TRANSPORTATION LOCAL PROJECT
Tunnels Classmates Can Relate
Bridges Classmates Have Seen It
Highways Classmates Have Used It
A Big Part of Civil Engineering Involves Transportation
5. WHAT DID IT TAKE TO COMPLETE “THE BIG
DIG”?
1982-Environmental Impact Documents
2007- Restoration of City Streets
7.8 miles of highway, 161 lanes miles
3.8 million cubic yards of concrete
More than 16 million cubic yards of soil excavated
1999 through 2002, about $3 million of work completed each day
About 5,000 construction workers were on the job
Jay Cashman, Modern Continental
118 separate construction contracts, with 26 geotechnical drilling contracts.
22 billion
6.
7. CONSTRUCTION PROBLEMS
Faulty Loose Fixtures:
September 2004
- Water seeps through traffic barriers in Interstate 93 tunnel
-Workers sandbagged one wall
-Independent engineers hired to study problem
-Reported that the tunnels may have more than 400 leaks
8. July 2006
-39-year-old woman killed after 12 tons of cement ceiling panels fell
on car.
-Lead to investigation where federal and state officials uncovered
additional problems almost on a daily basis
Bechtel: engineering, construction and management company’s reputation damaged
9. FINANCIAL PROBLEMS
- Over the course of the Project, costs kept increasing
- 2.6 Billion to 22 Billion
- Taxpayers ended up paying half of the project’s cost
ENVIRONMENTAL ISSUES
-Downtown area through which the tunnels were to be dug
was largely landfill and included existing subway lines as
well as innumerable pipes and utility lines that would have
to be replaced or moved.
-Tunnel workers encountered many unexpected geological
and archaeological barriers
-Glacial debris
- Foundations of buried houses and sunken
ships
