Researchers from UPV and the University of Vigo uncover the hidden mechanisms that prevent bridges from collapsing under catastrophic events

A team from the Universitat Politècnica de València (UPV) and the University of Vigo (UVigo) has just published in Nature the results of a study in which they have uncovered why bridges — specifically steel truss bridges — do not collapse when affected by a catastrophic event such as an impact or an earthquake. And their conclusions are similar to the behaviour of spider webs.

'We have shown that, just as spider webs can adapt and continue to trap prey after suffering damage, damaged steel truss bridges may still be able to withstand loads even greater than those they bear under normal conditions of use and not collapse,' says José M. Adam, researcher at the ICITECH Institute of the Universitat Politècnica de València, and Coordinator of the Pont3 project that this work forms part of, and that was funded by the Ministry of Science, Innovation and Universities.

Bridges are critical elements of transport networks, and their collapse can have very serious consequences, including fatalities and economic losses that can reach millions of euros for each day of closure.

"In addition, in the face of increasingly intense and unpredictable natural events and environmental changes that are accelerating the deterioration of bridges, it is essential to ensure that these structures do not collapse after a local failure. In this regard, we have made progress in our study," adds Belén Riveiro, researcher at the Centre for Research in Technology, Energy and Industrial Processes at the University of Vigo, and principal investigator of the Pont3 sub-project at the University of Vigo.

Some yes, some no

Until now, it has been unclear why initial failures of certain elements spread "disproportionally" in some cases, while in others, they barely affect the functionality of the bridge.

In their work, the researchers at the Universitat Politècnica de València and the University of Vigo have uncovered and characterised the secondary mechanisms that allow these bridges to be more resistant; they develop latent resistance instead of collapsing. “Thanks to this, we can understand how they can continue to bear loads after the initial failure of an element”, adds Carlos Lázaro, principal investigator of the Pont3 sub-project at the UPV.

Imitating and learning from nature: from lizards to spider webs

The work of the UPV and UVigo team provides new insights for the design of safer and more resilient bridges in the face of extreme events. It contributes to improving strategies for monitoring, evaluating and repairing existing bridges. In addition, their findings may help define new robustness requirements for steel truss bridges.

"All this with one fundamental objective: improving the safety of these infrastructures, which are so important and widespread in transport networks. And the key lies, once again, in nature; last year, we discovered how to prevent buildings from collapsing in the event of an extreme event by imitating lizards. This time, we have learned from spider webs, whose behaviour is similar to steel truss bridges. We have demonstrated this by comparing our work with another study published in Nature in 2012, which focused precisely on spider webs," concludes José M. Adam.

Initial support from the BBVA Foundation

The starting point of this work, published in Nature, was two Leonardo Grants awarded by the BBVA Foundation to Belén Riveiro (in 2021) and José M. Adam (in 2017). The first focused on the assessment of existing bridges and the second on the study of the mechanisms that make buildings resistant to local failures.

Reference

Reyes-Suárez, J.C., Buitrago, M., Barros, B., Mammeri, S., Makoond, N., Lázaro, C., Riveiro, B., & Adam, J.M. Latent resistance mechanisms of steel truss bridges after critical failures. Nature, 645(8079). https://doi.org/10.1038/s41586-025-09300-8