I-495 Haverhill Bridge Replacement Over Merrimack River

Project Overview:

This prestigious design-build is currently underway to replace the existing bridges carrying I-495 traffic northbound and southbound over the Merrimack River in Haverhill, MA. The project spans the length of the highway between exits 48 and 49, including two (2) 712-foot bridges. The bridge replacement, which will completely demolish and replace the existing bridges, is expected to take place in four stages through spring 2022. Accelerated Bridge Construction Techniques are being utilized to minimize disruption and reduce construction duration.

SPS services performed included: On-call bridge maintenance and operations; Real-Time Traffic Management system to notify commuters of the current traffic conditions; Construction of temporary construction access trestle; Installation of steel H-piles, drilled shaft foundations, cast-in-place concrete substructure elements; Installation of steel superstructures and cast in place concrete bridge decks with parapets; Bridge demolition; Full depth highway reconstruction and drainage improvements; and Mainline I-495 temporary crossover construction.

Key Challenges Overcome:

• Deteriorated condition of current structures | 24 hr seismic monitoring during activities of potential impact
• Maintaining 3 travel lanes throughout project duration | Use of Real Time Traffic Management system
• Mitigating environmental impact to endangered species | Temporary construction access trestle and environmental experts on-site