Sarah Mildred Long Bridge, Kittery, Maine - Portsmouth, New Hampshire

SEGMENTS, SUMMER 2017, VOL.61

Precasting complete at Sarah Mildred Long Bridge, Kittery, Maine — Portsmouth, New Hampshire

The Sarah Mildred Long Bridge Replacement Project is an important regional crossing linking Maine and New Hampshire across the Piscataqua River as part of the US Route 1 Bypass. The bridge was designed by FIGG/Hardesty & Hanover, Joint Venture, with FIGG accomplishing the segmental bridge spans. It is being built by Cianbro for Maine DOT (lead agency) and New Hampshire DOT.

With a focus on safety, function, economy, and aesthetics, the bridge will be made of 229 concrete segments for vehicles (top-level spans) and 126 concrete segments for heavy rail (lower level spans). All the segments have been precast at the Unistress Casting Facility in Pittsfield, Massachusetts. 280 of the segments are already on-site and erected. 75 bridge segments (all for vehicular spans) await delivery.

Construction of bridge foundations and piers is complete, including the four piers shared by the railroad bridge and overhead vehicular bridge. Segment erection is progressing rapidly. All segments for railroad cantilevers have been erected and connected with closures except the end span on the Kittery, Maine, side of the structure. All vehicular bridge cantilever segments have been erected on the Portsmouth, New Hampshire, side and two of those spans are completed with closures. Balanced cantilever erection of the remaining vehicular span segments on the Kittery, Maine side of the structure is currently underway and expected to be complete by the end of summer.

This highly unique bridge has a “resting” 56' vertical clearance over the navigational channel which provides for passage of almost 70% of the vessels. Its lift span, can be raised for a 135' clearance and lowered to carry trains. The piers for the lift span are made of precast concrete segments with hollow sections shaped to accommodate the lifting mechanisms.

Project Details

Owner:

Maine DOT (Lead Agency) and New Hampshire DOT
 

Designer:

FIGG/Hardesty & Hanover JV
 

Contractor:

Cianbro Corp.
 

Contractor Engineering Services:

 

Construction Engineering Inspection:

FIGG, Lamb-Star Engineering, L.P.
 

Precast Superstructure Segment and Tower Forms:

Ninive Casseforme
 

Superstructure Segment Precasting Facility:

 

Tower Segment Precasting Facility:

Port of New Hampshire (Adjacent to Site), Performed by Cianbro Corp.
 

Footing Tub Segment Precasting Facility:

Coastal Precast
 

Post-Tensioning Materials:

 

Bearings:

 

Expansion Joints:

 

Prepackaged Grout:

Euclid Chemical Company