Description of Services
This project involved the development of an accelerated bridge replacement methodology for the Long Island Bridge in Boston, a 3,500-foot-long critical transportation link connecting the mainland to Long Island—home to several essential public health facilities. The bridge consisted of four 750-foot, three-span deck truss units and a 250-foot simple-span through truss over the navigational channel.
As part of a previous General Engineering Consultant (GEC) assignment for the City of Boston Department of Public Works (DPW), Reliance Engineers Inc. led the development of a long-term bridge sustainability and replacement strategy. Given the vital nature of the crossing, the bridge could not be closed to traffic except for short, pre-scheduled durations. The project presented numerous challenges, including the need to maintain traffic throughout construction, restricted access under overland spans, 10-foot tidal fluctuations limiting barge operations, and multiple major utility lines carried along the bridge deck.
Reliance developed an innovative replacement methodology that included half-width reconstruction of the girder end spans, slide-out/slide-in replacement of the four deck truss units, and float-out/float-in replacement of the main navigational span. This strategy minimized service disruptions while addressing the logistical and environmental constraints of the site. The City of Boston adopted the proposed scheme and advanced the project to the final design phase. However, due to advanced structural deterioration identified during a subsequent inspection, the bridge was ultimately demolished for safety reasons.
During the initial phase, Reliance also provided geotechnical exploration services, assessments of existing pier reuse, utility relocation planning, and bridge demolition strategies. As part of the ongoing bridge replacement effort, Reliance is now serving on the final design team, contributing to bridge design, abutment and pier retrofit, and continued technical support.
