Rose Fitzgerald Kennedy Bridge Over the River Barrow: Design and Construction of a Multispan Extrados Concrete Bridge

The Rose Fitzgerald Kennedy Bridge spans the River Barrow with two 230-m (755-ft) long main spans. It is an extradosed bridge with three towers, and four spans that are supported by cables in addition to several approach spans to complete the 887 m (2,910 ft) length of the whole superstructure. The design paid special attention to landscape integration, durability, and planning requirements. The analysis was required to address challenges related to structural efficiency under service loads and local code considerations, wind effects on traffic, ship collisions, and fire events analysis as well as construction issues related to the extreme slenderness of the superstructure. The design decision-making process and value engineering were heavily constrained by the contract requirements, which led to a solution that slightly departed from pure engineering optimization but that allowed for the addressing of local requirements and integration with the surroundings. This paper presents a case in which engineers had to comply with specifications set by the Administration, which did not correspond to optimum economic engineering solutions. Other criteria such as the aesthetics or ensuring minimum disruption to the landscape are also valuable, especially in the long term, and may drive engineers to nonstandard proposals.