After 55-years of service, a critical portion of Boston's heavily traveled Storrow Drive may be facing a major overhaul. The Eastbound tunnel is in serious need of repair and any of four options could tie up city traffic for two-to-four years.
Mass. Dept of Conservation and Recreation
Starrow Drive tunnel, built in the 1950s, needs makeover.
The two-mile long artery, which runs along the southern shore of the Charles River in the Back Bay section, carries about 120,000 vehicles per day. But the 1,280-ft- long eastbound tunnel suffers from deteriorated concrete sections and corroded steel members. There is beam corrosion in the roof, as well as spalling concrete and exposed rebar and the roof, and walls and base slabs all leak causing ice problems in the winter. Cast-in-place ramp walls also are cracked and leaking. "We are looking at four major options," says Wendy E. Fox, press secretary, Mass. Dept of Conservation and Recreation. "Estimated costs could run anywhere from $24-million to $200-million with construction starting in 2010." Including ramps about one half-mile could be torn up during construction. She notes in the next month or so the agency will come up with a final plan for draft environmental review while it continually inspects and repairs the tunnel to ensure public safety.
In 2001 DCR awarded a $1.9-million, 10% design and draft EIS contract to Simpson Gumpertz & Heger, Inc, Waltham to get the ball rolling. Paul L. Kelley, SGH senior principal notes SGH has held a number of contracts with DCR over the years, including an emergency roof steel beam repair in the mid-90's but he states the structure is safe and poses no immediate threat to the public. "The tunnel is approaching the end of its service life and will need about $2-million to $5-million in repairs," he says. "Major work will be done to the concrete on the approach walls and underside of the roof, expansion and construction joints and the steel will be maintained."
At the time of construction building the 11-ft, 4-inch-high tunnel was a challenge. "The tunnel is a 35-ft wide cut and cover structure with two different roof structures. Half of it has a steel beam roof topped by a 10-inch concrete slab that widens into 63-ft at an intermediate off ramp then narrows back down to a two-lane tunnel with a cast-in-place 24-inch-to-36-inch roof," he says. There is water intrusion through the roof causing icicle problems and floor leakage causing road surface problems. The tunnel is closed every July 4 for a major concert on the nearby Esplanade while maintenance repairs are made.
The four options now under consideration include: rehabbing the existing tunnel with major steel replacement and new slabs costing about $52 million, eliminating the tunnel and creating a surface parkway at $24 million, constructing a new westbound tunnel with new eastbound surface parkway and eliminating the existing tunnel at $81 million, and building two new tunnels at $200 million. "Once the preferred alternative is chosen, SGH brings the design up to 25%," says David J. Lenhardt, DCR project engineer. "After that the state will determine whether to retain SGH or solicit a new firm to finish the design. A construction contract will be competitively bid probably in late 2009."