GM2’s services, for this $2B multi-faceted construction project, included structural peer review, structural analyses and design, survey and construction engineering and inspection. Major project components include operational, safety and capacity improvements to 7.2 miles of I-95, a new 10-lane extradosed bridge, and a new I-91/I-95/Route 34 Flyover.

The Flyover entailed a curved twin box, girder steel bridge with a 1,886 FT length and maximum span of 285FT comprised of separate 3- and 5-span bridges. Challenges included determining span configurations, global stability, constructability and the sequence of construction, thermal movements, and identifying cost effective detailing techniques for the steel. GM2 utilized a high performance steel and complex modeling of thermal movements and associated bearing joint details as part of their solution. Designing the new curved girder code utilizing software that was not fully compliant with all aspects of the code required meticulous checking of software results with alternate methods and working very closely with the software developer to correct all discrepancies.