Bridges all over the world are developed with the potential to withstand earthquakes. Concrete reinforced with steel are utilized to handle bridge shaking and movement, but once the seismic event is over, the bridges always require inspection and often need repair.

A group of civil engineers at Rice University and Texas A&M are working together to create an innovative approach to making repairs easier and more effective. They are developing computer modeling software that can predict the effects an earthquake would have on a specific bridge, and how to repair it as close to the original design as possible.

The model reports will be available through open-source network “OpenSees” for other engineers to freely assess what types of repairs are favorable for a specific structure.

This illustration shows the sequence of earthquake damage and repair involved in restoring columns to their original strength. Illustration by Mohammad SalehiThis illustration shows the sequence of earthquake damage and repair involved in restoring columns to their original strength. Illustration by Mohammad Salehi

"What we mainly care about is life safety, of course, and we know that after a strong earthquake, we are going to see some level of damage to the structure," he said. "If a column is severely damaged, it might need to be replaced, but that can be prohibitively expensive. Our computer models can help engineers determine whether the column can be repaired in a cost- and performance-effective way."

Predicting earthquake damage and analyzing effective repair strategies

The concrete and steel columns are referred to in the models as “fiber” elements. The data can predict how the materials will respond to arbitrary loading considering the nonlinear stress-strain performance of the building and repair materials. The engineers can manipulate the model fibers to analyze how repaired columns would perform when faced with another seismic event.

Not only will this be useful for earthquake repairs, but general wear and tear of bridges. "We're seeing more and more that existing infrastructure is deteriorating due to corrosion and other causes," DesRoches said. "So this general methodology can be applied in terms of understanding how repairs can restore and improve the performance of deteriorating structures, too."

To contact the author of this article, email ccooney@globalspec.com