I-59 / I-20 ELEVATED INTERSTATE
The I59/20 CBD carries heavily traveled Interstate 59 and Interstate 20 through downtown Birmingham. The new bridges will replace existing steel plate girder bridges built in the early 1970s. The new bridges will carry up to five travel lanes and shoulders in both the eastbound and westbound direction. Alignments of the new bridges will follow the existing alignments, with construction progressing with bridge demolition.
Separate eastbound and westbound structures, each with a length of approximately 6,500’, will carry mainline traffic. Each of these bridges is comprised of two precast box girders joined by a longitudinal closure joint. The combined widths vary from 70’ to 94’. Span lengths vary from 110’ to 165’ and will be constructed by the span-by-span method with external post-tensioning tendons. These mainline bridges, along with two segmental ramp structures, will total 1 million square feet of elevated bridge deck.
Corven Engineering created the final design of the precast segmental superstructure.