Earthquake safety tool listens to a building's ambient vibrations

Deciding when it’s safe for a building’s residents to move back in after an earthquake is a major challenge for civil engineers. The new technique, which works by measuring a building’s ambient vibrations, promises to improve the accuracy of these assessments.

“We took systems that are already used to measure the condition of bridges, and applied them to the assessment of buildings damaged by an earthquake,” said Pierino Lestuzzi, one of the researchers on the project.

Critically, he added, the method doesn’t require knowledge of the pre-earthquake state of the building to perform t the assessment.

Engineers currently perform this diagnosis using a visual assessment carried out according to an appraisal form developed by Italian researchers. This approach proved highly effective after two major earthquakes in central Italy in 2009 and 2016. But even though a visual assessment is essential for spotting the damage caused to a building, it takes a long time to complete – some 2–3 hours per building – and is fairly complicated and subjective. And it does not eliminate the uncertainty about whether a building could withstand aftershocks.