Steel Bridge Team Qualifies for Nationals

By Jeff Viano

The Steel Bridge Team traveled to Purdue University in West Lafayette, Ind., on April 28 to compete in the Great Lakes Regional Competition, sponsored by the American Society of Civil Engineers and the American Institute of Structural Engineers. The Illinois team faced ten teams this year from Illinois, Indiana and Wisconsin, including the powerhouse team from the University of Wisconsin at Madison. The Illinois team placed second only to Wisconsin, a performance good enough to qualify the team for the national competition in Northridge, Calif., on May 28.

The rules for the bridge competition this year dictated that the bridge be 20 feet long and have a single span. The bridge had to be designed to resist deflection from a 2,500-pound load placed at a random location along the bridge deck. In addition to this, the bridge had to be designed for ease of construction, as construction speed is a large factor in determining the score at the competition.

The final design for the bridge was a trapezoidal truss with six rods connecting the top cord of the truss to the roadbed. This design allowed the bridge to be built without the need to enter the “river” the bridge spanned. In the end, the bridge was designed for ease of construction and lightness, often at the cost of deflection. These tradeoffs helped us maximize our score in two important categories.

Our 240-pound bridge performed very well at the competition, with a maximum deflection under the 2,500-pound load of 0.3 inches. Our building speed was just under 12 minutes with only four builders, good enough to beat every team except Wisconsin. Our performance at regionals earned the team second place trophies in lightness, construction speed, construction economy, aesthetics, and overall performance.