Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=222339
Story Retrieval Date: 8/20/2014 3:47:25 AM CST

Top Stories
Features

Washington bridge collapse could be a wake-up call

by Theresa Chong
May 30, 2013


BRIDGE_CRACK

Theresa Chong/MEDILL

Deterioration along the underside of the bridge near Clybourn Station.

BRIDGE_CLOSEUP

Theresa Chong/MEDILL

Large crack on the bridge near Clybourn station.

A bridge collapsed when an oversized truck crashed into one of the support beams on Skagit River Bridge on Interstate 5 tossing two cars and three people into the river recently.

After the collision, the truck driver crossed the bridge and pulled over to the side, which is when two cars behind him – a pickup and a Subaru - plummeted into the river.  I-5 is a key travel corridor on the West Coast connecting Washington state with Canada.

“It is one of a series of fairly frequent alarms nationwide--some louder than others,” said Robert Barnes, a civil engineering professor at Auburn University in Alabama. “Until we fix our national funding structure for highway maintenance (gasoline taxes), we will just keep pressing the snooze button and rolling over.”

“We can always use more funding but most of our bridge work is funded through federal government or through the state,” said Pete Scales, director of public affairs at Chicago Department of Transportation.

In the case of accidents such as the one that happened on I-5, the blame game might not be so clear-cut. Barnes explained why: “If the driver had heeded low-clearance warnings, the collapse could have been prevented. On the other hand, this collapse could have been prevented with a new bridge built in accordance with modern vertical clearance standards.”

He also said that state transportation officials are constantly trying to prioritize limited funds for their projects.

When it comes to civil infrastructure, Dave Devinger, a corporate attorney in Chicago, said that he didn’t mind that some of his taxes go to maintaining bridges because “it’s a matter of public safety.”

Chenyang Lu, a professor of computer science at Washington University in St. Louis, and his team are currently developing “wireless structural control systems.”

“These are real-time control systems that monitor structural response using wireless sensors and control the structures using actuators,” he said.

Since rebuilding every deteriorated bridge is not cost effective, “We need to retrofit these existing bridges with monitoring and control systems to make them more resilient,” he said. “Wireless structural monitoring and control systems provide promising technology for our aging bridges and civil infrastructure in general.”

The American Society of Civil Engineers'  “2010 Report Card For Illinois’ Infrastructure” also gave the state a D+ rating, citing 2311 structurally deficient bridges, which is 8.7 percent of Illinois’ bridges.

For instance, according to the Illinois Department of Transportation website, the bridge near North Ashland Avenue and I-90 in Chicago was inspected last month and declared structurally deficient, functionally obsolete, and there is a high priority to correct the bridges’ under clearance.

The civil engineers' website stated that although there is a slight decline in the average age of the nation’s bridges, 30 percent of the bridges have already surpassed their 50-year-design life.

“Many of challenges faced by the Washington DOT are challenges for all state and local transportation agencies. There is nothing about this situation that is unique to the state of Washington,“ Barnes said.

Within the city of Chicago, Scales said, “We do a thorough inspection every other year. We are on top of servicing the quality of our bridges.”

Devinger said despite Chicago’s aging infrastructure, he doesn’t reroute his travel plans to avoid specific bridges because he “assumes they're safe.” But, when it comes to structural improvements to existing bridges there’s “a lot of work to do,” he said.