NH 12A Bridge Replacement

Lebanon, New Hampshire | City of Lebanon

The City of Lebanon needed to replace a functionally obsolete crossing with inadequate geometry that was at the end of its service life. The three-span, 145-ft-span steel stringer bridge that crosses over the New Hampshire Railroad serves NH 12A at a skew with the railroad tracks immediately adjacent to the congested intersection with US 4. The project receives Municipal Off-System Bridge Replacement and Rehabilitation program (MOBRR) funds. D&K was selected to value engineer the replacement design prepared by another consultant and subsequently to design the replacement. D&K’s design installs new abutments using MSE walls with tiebacks and adjusts alignment by approximately ten feet to reduce the bridge span by approximately 60 ft. The project follows the New Hampshire Local Public Agency (LPA) process.

Markets:

Project Elements

• Conversion of 145-ft, three-span structure to one 80-ft-span
• Roadway realignment including reconstruction of 1,150 LF of roadway and 500 LF of access road
• Temporary pedestrian bridge for construction phase
• New abutments use mechanically stabilized earth walls with tiebacks
• Bridge is widened by the addition of left-turn lane from adjacent intersection