91视频

There is a towering presence taking up most of the space in a former greenhouse at Portland State University.

It’s a 44-foot-long, wooden, cable-stayed bridge model built by a team of undergraduate engineering students over the past six weeks as a practical learning exercise. The structure, modeled after TriMet‘s new Tilikum Crossing transit bridge, could also later serve as a teaching tool to inform high school students about engineering.

鈥淲e have a lot of projects with hands-on experience,鈥� PSU civil and environmental engineering instructor Evan Kristof said. 鈥淪omething always clicks when the students do hands-on projects. Something like this, where we’re modeling it after a real world structure 鈥� it always helps.鈥�

Independent teacher Elliot Apatov, who has instructed Portland-area middle and high school students on bridge and crane building for nearly 20 years, initially conceived the project for younger students. When Lincoln High School, in Portland’s Goose Hollow neighborhood, didn’t have room for the bridge, he approached the dean of PSU’s Maseeh College of Engineering and Computer Science. This led to a partnership featuring Kristof and six engineering students to build on the PSU campus a large-scale bridge model with 12-foot-tall towers able to hold up to 9,000 pounds.

鈥淚t’s an engineering class, so we have to do it to the specs of a real bridge,鈥� Apatov said.

After teaming up with PSU, Apatov secured donations from design and build companies to construct the model bridge. Lumber no longer needed for the Sellwood Bridge replacement project was provided by Slayden-Sundt, the joint venture of Slayden Construction Group and Sundt Construction. Other donations came from Portland Fasteners, West Coast Wire Rope, Metal Enterprises, John W. Negus Co. and KPFF Consulting Engineers.

鈥淭he industry people realize that teaching kids engineering and construction is very important,鈥� Apatov said.

Because the completed bridge model occupies most of the space in the PSU greenhouse, it must soon move elsewhere to make room for materials testing and other regular engineering curriculum activities. Apatov is hoping to find the bridge a permanent home at a Portland-area high school where it can be used to demonstrate engineering concepts. He also is planning to create an educational video with PSU engineering students who will explain the basics of designing and constructing the bridge.

Apatov is not trained as an engineer, but he said his experience teaching and making furniture has served him well in developing a bridge curriculum for middle and high school students. In his classes, students build large-scale bridge models and test their capacity with weights. In another activity, a rope-and-wood 鈥渉uman suspension bridge鈥� is formed 鈥� several students on either end experience compression forces while serving as towers holding up a student balanced on the deck.

鈥淚 don’t do Popsicle stick bridges,鈥� he said.

In his years of teaching, Apatov said he’s learned that students are often most engaged when they can experience a concept firsthand rather than merely read about it.

鈥淭hey learn that they need math to build a bridge,鈥� he said. 鈥淚f you screw it up, it falls down. They run the calculations, but when they actually do it, they believe that it happens.鈥�

The same can be said for college-level engineering students, Kristof said. Building a scale bridge model helped his students see beyond textbooks and formulas.

鈥淔or the most part, it’s really abstract,鈥� he said. 鈥淚t blows their mind that what they’re doing actually translates into the real world.鈥�

Kristof said recruiters for engineering firms often value recent graduates’ practical experience as much, if not more, than good grades.

鈥淭hat’s what employers keep telling us; they want real world experience,鈥� he said.

Namer Ezat-Agha, a junior in PSU’s civil engineering program, said helping build the model bridge solidified his career ambitions.

鈥淚 had never had this experience,鈥� he said. 鈥淢y idea was to go into structural engineering, so this gave one other positive push in that direction.鈥�

Working on the bridge gave Ezat-Agha a renewed appreciation for the Tilikum Crossing and Sellwood Bridge projects under construction. He also was able to put to use what he learned in class.

鈥淚t was kind of cool actually applying what you learn in books,鈥� he said.

While the model bridge was under construction, Ezat-Agha said he frequently sent pictures of it to his friends. He’s proud of what he and other PSU engineering students accomplished.

鈥淚 can say I built a bridge,鈥� he said.