Continuous Precast, Prestressed Concrete Girder Bridge Systems

As most prestressed concrete slab-on-girder bridges are simply-supported, there is limited experience and a wide variety of design and construction approaches when making this class of bridge continuous with longer spans. Continuity connection details used for precast, prestressed concrete girder bridges across the United States that allow span lengths beyond 150-ft are investigated. Several methods are reviewed that have been used in the past to provide continuity and increase the span length of slab-on-girder prestressed concrete bridges. Particular emphasis is given to Bulb Tee and I-girder systems that have been used extensively over the years. Construction issues that should be considered during the concept development and design stage are highlighted. Splice connections are categorized into distinct types including fully prestressed, partially prestressed, and fully reinforced (non-prestressed) concrete systems. Advantages and disadvantages of each approach are discussed with focus on construction and long-term serviceability. Finally, it is concluded that while all systems have their merits, a mixed solution is perhaps the most desirable.