According to the U.S. Department of Transportation, of the more than 600,000 bridges across the country as of December 2008, more than 12 percent were categorized as structurally deficient and more than 14 percent were categorized as functionally obsolete.Steel bridges offer viable design solutions for bridge owners because they are durable, cost-effective, and offer ease of maintenance and construction.
The structural advantages of using steel include its high strength, durability, and light weight, which mean lighter foundations and lower erection costs. Steel is ideal for short-span bridges because of its durability, ease of maintenance and ease of construction.
Steel’s strength makes it highly resistant to extreme natural disasters, such as earthquakes. The 1994 Northridge, California earthquake destroyed the surrounding transportation infrastructure. However, 96 percent of the existing steel bridges were completely undamaged, even though they were designed using 1940s technology.
Today, designers and engineers are specifying new high-performance steels that were developed through a partnership of AISI, the U.S. Office of Naval Research and the Federal Highway Administration. These new steels have a yield strength of 50 ksi, 70 ksi and 100 ksi, have superior toughness, and can be welded with little or no preheat. Alternative bridge form designs are being developed that promise even greater design flexibility and cost efficiencies.
Weathering steels are cost-effective and durable. These steels contain certain elements that allow them, when properly exposed to the atmosphere, to form a protective oxide patina or coating. Studies show that using weathering steel reduces both initial and life cycle costs.
High-Performance Steel Bridges
Weathering Steel Bridges
Short Span Steel Bridges
2/6/2017 - The new 200th Street Bridge in Buchanan County, Iowa is the focus of a discussion and demonstration of the many benefits of steel buried bridges.
10/21/2016 - Dr. Karl Barth and former student Dr. Greg Michaelson helped to develop and introduce a new way to design short span steel bridges.