CABLES OVER THE MISSISSIPPI

As the designer of the Great River Bridge over the Mississippi between Gulfport, Ill. and Burlington, Iowa, Sverdrup Corp., St. Louis, had to find a way to connect the new five-lane crossing to old roads while at the same time maintaining a 60 ft navigational clearance over the river. The resulting $50 million cable-stayed structure features an asymmetrical, single-tower design and a curved deck that eliminated the need for major changes to the grade approaches. Two planes of cables support the 660 ft main span, 405 ft side span, and the 180 ft suspended span that, along with a tie-down pier, helps balance the load. In addition to being just as economical as a symmetrical design, moving the tower towards the Illinois side increased the overall stiffness of the structure and improved navigation in the channel. Now open to traffic, the bridge replaces the 77 year-old MacArthur Bridge and improves the flow of cars and trucks on U.S. Route 34.