New technique aims to extend bridge life, save dollars

A large number of U.S. bridges are reaching the end of their lives and are subjected to heavier traffic than originally intended, but replacing them costs serious money. As a result, affordable solutions to safely extend bridge life are urgently needed.

In a study sponsored by CTS, researchers modeled a response modification technique in which a device is added to aging bridge components under repeated heavy loads. The technique could change how a bridge responds to a specific load—helping it disperse weight from a heavy vehicle, for example.

To test this technique, the researchers—led by Professor Arturo Schultz and Assistant Professor Steven Wojtkiewicz of the Department of Civil Engineering—used an existing computer model of an in-service Minnesota bridge. They found the response modification technique would effectively reduce stress on vulnerable bridge connections. As a result, the stress ranges were reduced by 39 percent, which could lead to a bridge life extension of up to 61 years. In a follow-up study, researchers discovered using multiple modification devices could extend bridge life even further—by as much as 81 years.

Overall, their results indicate that, combined with bridge health monitoring and advanced sensors, the device has the potential to extend bridge life by decades at a fraction of the cost of bridge replacement.

Additional research is needed to investigate optimal placement of the device and the best methods for attaching the device to the bridge.

This story has been reprinted from the Center for Transportation's CTS Catalyst with permission.