Precast segmental bridges had been built in New England before, but each time a temporary precast plant had to be set up on the project site. In 1997, Unistress decided to change that, and our opportunity lay 150 miles to the east. The Massachusetts Turnpike Authority had undertaken the nation’s largest-ever urban highway reconfiguration, the Central Artery/Tunnel Project in Boston.
Challenge
Because of their size and weight, precast segmental bridges are usually cast on or near the job site. In 1997, Unistress decided to re-think that approach, starting with the nation’s largest-ever urban highway reconfiguration, the Central Artery / Tunnel Project in Boston.
Solution
Unistress cast the segments at our plant in the Berkshires, eliminating the need to set up a facility in the heavily congested downtown area. Unistress met the challenges of specialized match-casting techniques, complex rebar cages, and exacting tolerances while meeting an unyielding delivery schedule.
Role of Design Assist
As part of the Value Engineering process Unistress modified the design to integrate precast segments in to the piers to accelerate construction and improve seismic resistance and saw cut the segments attached to the straddle bents to overcome alignment issues.
