Walking the work zone

Many studies have shown the benefits of education in science, technology, engineering and mathematics. One of the most effective ways of inspiring children to embrace STEM is to give them an up-close look at science in action.

Two classes of Veneta Elementary School second graders got that chance with their teachers and parent chaperones. They capped a "day of science" with a visit to the Interstate 5 Willamette River Bridge project, where they stepped behind the orange cones to see how a bridge is built.

Their day began with a nature walk and a trip to the Science Factory near Autzen Stadium in Eugene. Upon arrival at the construction staging area, Karl Wieseke, ODOT construction manager, led his group of students through safety protocols and let them suit up in adult-size reflective vests, hardhats and goggles. Then they toured the project site, where they learned about building bridges, including the process of mixing concrete, which drew laughs thanks to the analogy Hamilton Construction Manager Con O'Connor provided for making a cake.

A separate group of students in the Churchill High School STEM program visited the same project, hosted by OBEC Consulting Engineers, the architecture and engineering firm for the I-5 bridge project.

They happened to catch an outstanding day for viewing multiple on-site activities: Work was underway on two phases of box girder construction next to some completed box girder spans; the Bidwell deck-paver was still ready for service on the adjacent span.

Standing on the vast work bridge just above water level, the students listened to tour director Brad Larsen, engineer at OBEC, explain the profile of the bridge's arches, which are not true arches - their profile is too flat. The students were able to observe the process by which the completed southbound arches had been poured in place on-site.

The students were among many groups of Eugene-Springfield residents who took advantage of the bridge's proximity and the project team's hospitality to learn more about bridge building live and in person.

Sharing the wealth

Because of its complexity and unique design challenges, the Sandy River Bridge project presented a unique opportunity to pass along knowledge and expertise. This sharing of knowledge took place in a variety of forms.

Baby boomers - born between 1946 and 1964 - make up more than 40 percent of the current construction workforce. Over the next decade, this generation will begin to retire. If a new replacement labor pool isn't trained, the industry will soon be understaffed.

Apprenticeship programs are one way that boomers can pass on their invaluable skills to the next generation of tradespeople, and work-zone visits are an essential part of such training. As a way to bridge this gap, the bridge program hosted two groups of future apprentices at the Troutdale project site.

During separate visits, 12 students from the Portland YouthBuilders construction program and six students from the Evening Trades Apprenticeship Preparations program observed what it takes to build a bridge that carries thousands of motorists every day. Their visit to the Sandy River Bridge site gave the groups a chance to learn about highway construction trades firsthand from the current generation of skilled workers who have built their careers in the industry.

Beyond training future generations of tradespeople, opportunities exist to share knowledge with other professionals from different parts of the world. Joe Hampton, project manager for prime contractor Hamilton Construction, and ODOT Quality/Quantity Review Specialist Thor Alvarado hosted visitors from the Bridge and Structures Division of the Japan National Road Department and the Japan Earthquake Disaster Prevention Division.

Long steel (rather than concrete) spans were designed to eliminate the number of pilings in the river, increasing the bridges' resiliency in an earthquake as well as protecting the quality of water. The Japanese engineers were very interested in the strategies the bridge program had used to mitigate flooding in the broad and shallow river basin near the confluence with the Columbia River, such as the logging machines that cleared debris before and after flooding in 2011 and the gantry crane that eliminates the need for a work bridge.

Need for speed

Rapid replacement is a construction technique in which a new bridge is built next to the old one while site preparation and demolition takes place. When the new structure is completed, it can be slid into place quickly, often over a single weekend. The use of rapid replacement on the bridges on either side of the Elk Creek Tunnel on Oregon 38 spared local drivers six months of either 40-mile detours or daily 20-minute delays due to lane closures.

This technique is expensive, but ODOT defrayed the cost of rapid replacement for the Elk Creek bridges by obtaining a $1 million grant from the Federal Highway Administration's Highways for LIFE program.

As part of its commitment to Congress in allocating the money, the Highways for LIFE program showcases model projects to update other highway experts on the latest innovative construction techniques. In 2008, FHWA invited 35 transportation professionals from Montana, Washington, Colorado, New Mexico, Maryland and Washington, D.C., to observe the second of the two bridge "rolls."

Several attendees visited the bridge site on a Friday evening to watch the final demolition of the old structure. Operators of the enormous compression hammers deftly set their tracks on the beams and busted up the deck right underneath their machinery. On Saturday morning, the group reconvened in Elkton for the bridge slide. The process took about an hour, as the new bridge, which had been built on hydraulic skids, slid into place. The bridge was open to traffic on Sunday evening.

As Phillip Ditzler, Division Administrator of the FHWA's Oregon office, noted at the time, "While rapid replacement is often used to speed up bridge construction in high-traffic urban areas, it's also effective in rural settings with steep canyons, deep river beds or tunnels, such as over Elkton Creek."