Building a Steel Bridge

NUASCE Steel Bridge Team, led by captain Christine Lai, placed second in minimizing deflections at the 2015 New England Steel Bridge Competition.

Source: News @ Northeastern

Northeastern University’s steel bridge team will compete in the American Society of Civil Engineers’ 2015 New England Steel Bridge Competition at Merrimack College on Friday. More than a dozen teams, from Boston to Quebec, will converge on the North Andover, Massachusetts, campus, where their bridges will be judged on factors ranging from deflection and lightness to aesthetics and construction speed. Here are five things you need to know before the competition begins.

Time Well Spent
A team of 20 Northeastern students spent eight months designing, fabricating, milling, and welding the bridge. The engineers-​​in-​​training designed the structure in SOLIDWORKS, the computer-​​aided design program, and then performed a series of virtual tests on their 3-​​D drawing using SAP and Mastan, two interactive structural analysis programs. “We discovered some weak spots in the bridge using these programs, and then we made some minor modifications to the structure,” said team captain Christine Lai, a fourth-​​year civil engineering major. “In the end, the bridge held up very well.”

Truss Me…
The students designed a 17 feet long, 200-​​pound truss bridge. That is, a bridge whose load-​​bearing superstructure is composed of a structure of connected elements forming triangles. “A truss bridge is the most stable kind of bridge,” said Lai, E’16. “The utilization of triangles in all forms is usually what bridge-​​makers go for.” This year’s design required more steel than last year’s design, which upped the time it took to fabricate the structure—a trade-​​off that should prove to be well worth the extra work. “Hopefully,” said Lai, “the bridge will hold up well and pass the loading test in the competition.”

Zach Lozon, E'19, welds a truss member in the basement of Richards Hall.
Zach Lozon, E’19, welds a truss member in the basement of Richards Hall.


The Power of Co-​​op
Lai showed the team’s design to her colleagues at Jacobs Engineering, where she is working on the Longfellow Bridge rehabilitation project. Her co-​​workers approved of the plan, she said, noting that the group designed the scale model to replicate the form and function of a real-​​world bridge. “Even though our bridge is only representative of the real thing,” said Lai, “we still had to utilize engineering concepts like loading, pressure, tension, and compression.”

The Power of Class
Many of the group’s students have applied what they’ve learned in class to the design and fabrication of the hefty structure. Most of the team’s veterans, Lai said, have taken the structural analysis and steel design courses led by Andrew Myers, the assistant professor of civil and environmental engineering who serves as the group’s faculty adviser. “Professor Myers was the perfect fit for the team,” she said, “and really helped us use Mastan more effectively during the project’s design phase.”

‘I Want to Build Bridges’
Myers noted that working on the steel bridge project unequivocally prepares students for careers in structural engineering. “Most of the work in the standard engineering education is done on paper and on the computer,” he said, “but bringing the challenge to the real world provides a different perspective that can not be found in text books.” Lai, for her part, wants to dedicate her to career to building beautiful bridges, like the Helix Bridge in Singapore. “Working on the steel bridge team has influenced my decision to get into the structural field,” she said. “Now my entire life is revolving around building bridges.”

Related Faculty: Kurt Braun, Michael MacNeil, Andrew T. Myers

Related Departments:Civil & Environmental Engineering