Nearly 39,000 people rely on the Sumner Tunnel every day to link them from Logan International Airport and East Boston to the North End and Downtown. "The Sumner Tunnel was one of the first tunnels in Massachusetts for car travel, one of the oldest tunnels in the country at nearly 100 years old, and it's due for a major restoration and renovation," said Lt. Gov. Kim Driscoll, Transportation Secretary. Routine inspections of the 1934 Sumner Tunnel revealed structural and safety issues, prompting the decision to execute a complete renovation. The tunnel's ceiling was deteriorating after 89 years of daily wear and tear, with chipped and crumbling concrete, and exposed, rusted reinforcing.
United Concrete Products manufactured 788 precast concrete arch ceiling panels and 147 precast/prestressed concrete flat panels for the Sumner Tunnel's ceiling as part of a larger restoration project to keep the tunnel in service. The project's primary goal was to restore the tunnel to comply with modern safety and design codes while accelerating the construction schedule to minimize disruption to the public.
United Concrete Products served in a design-build capacity and contributed to the accelerated schedule by streamlining the designing, planning, and construction processes by recommending precast, prestressed concrete to restore the tunnel's ceiling and meet the Massachusetts Department of Transportation's timeline requirements.
The 788 precast concrete arch ceiling panels and 147 precast/prestressed concrete flat panels were manufactured off-site at United Concrete Products Yalesville, Connecticut location in only 6 months and then transported to the construction site. The precast concrete arch ceiling panels span 21'9", have a 5'7" rise, and are 6" thick while the precast/prestressed concrete flat panels are 8' wide by 19'6" long and 6" thick. Off-site production of the tunnel's new high-performance precast concrete panels ensured stringent quality control and eliminated unnecessary trades on-site, which resulted in cost savings and accelerated construction.
The full tunnel closure was originally expected to last seven months. However, prefabricating the high-performance precast concrete panels off-site allowed additional construction work to occur 24/7 inside the tunnel, reducing the full tunnel closure to four months. Furthermore, 40 individual weekend shutdowns were avoided by carefully coordinating full tunnel shutdowns, reducing 10 months from the construction schedule. During weekend shutdowns, J.F. White Contracting Co. installed approximately 16 precast concrete arch ceiling panels per day by utilizing steel transport and lifting racks provided by United Concrete.
The Massachusetts Department of Transportation can safely rely on the renovated tunnel for another century thanks to the inherent benefits of precast, prestressed concrete, including reduced maintenance, an extended life cycle, fire resistance, sound mitigation, resiliency, and durability.