Scope of Work
As the Construction Manager/General Contractor (CM/GC), Cianbro constructed the Sarah Mildred Long Bridge replacement structure located on the Piscataqua River. The existing steel vertical-lift bridge carries the U.S. Route 1 Bypass, providing a critical link between Kittery, Maine, and Portsmouth, New Hampshire. The new 2,800-foot concrete vertical-lift bridge was constructed at a higher elevation than the existing, with a vehicular structure stacked over a railroad level, as well as a longer lift span at 300 feet.
Project Details
- Removed existing structures
- Constructed concrete roadway and railroad superstructures
- Constructed a high-quality and reliable 4,000,000 pound 300-foot long steel lift span
- Constructed four angular lift span towers
- Avoided and minimized project impacts to the roadway, railway, and maritime traffic; local businesses; and communities during construction
- Erected 500 precast concrete segments, including 126 precast railroad segments, 229 precast vehicular segments, and 88 precast tower segments
- Installed four 20 foot-diameter, 100-ton counterweight sheaves
- Installed 29 drilled shafts, composed of 8,000 yards of concrete and 3,000,000 pounds of rebar
- An additional 20,000 yards of concrete containing over 2,500,000 pounds of rebar were cast-in-place on the project
- Over 300 miles of post-tensioning strand was installed, tensioned and encased in nearly 12,000 bags of "cable" grout
- Over 200 team members on site at the project's peak
- Managed environmental time of year restrictions, in water work windows, hydroacoustic and turbidity monitoring
- Installed open finger joints with fabric drainage troughs
Lean, Innovative and Unique Project Solutions
As a member of the Integrated Project Team (IPT), Cianbro worked collaboratively with the Maine and New Hampshire Departments of Transportation as well as Figg Engineering and Hardesty & Hanover, on New England’s first CM/GC alternative delivery bridge project. Cianbro maximized the benefits of the CM/GC process by focusing on the design and construction approach to enhance safety, improve schedule, and increase project value while adhering to the budgetary goals.
