Susannah Eliott is CEO of the Australian Science Media Centre
Three days on from the collapse of the Morandi Bridge in Genoa, Italy, rescue teams are still looking for bodies and everyone is asking questions. How could such a large bridge fail so catastrophically?
Dr Colin Caprani, a Senior Lecturer in Structural Engineering at Monash University said people rightly expect that bridges won’t fall down, but he warned there are no absolutes.
“Engineering science is not perfect, and there is much we do not yet know,” he said.
“Worse, without structural health monitoring of aged structures, we have little opportunity to learn from failures and make better predictions about future collapses.”
While the likelihood of dying while on a collapsing bridge is still incredibly small (roughly 100 times less than the risk of being struck by lightning), according to Professor Caprani many bridges are at the end of their design lives and need urgent attention.
“The increasing number of collapses we are seeing in recent years is likely to worsen as deterioration takes its toll, and inspection and maintenance programs continue to have their budgets reduced,” he said.
Knowing when a bridge is at the end of its life is no small matter. “It is surely time that smart sensing solutions are used across all our aged infrastructure to protect people from events like in Genoa,” said Professor Caprani.
Identifying how vulnerable a bridge is before it collapses is key according to Professor Sujeeva Setunge, Project Leader for the Bushfire and Natural Hazards CRC.
She told the AusSMC that “the collapse of the Genoa bridge demonstrates the urgent need for understanding the vulnerability of bridges under effects of combined loading of normal traffic and natural hazards while allowing for the natural degradation of structures”.
So, could such a bridge collapse happen in Australia? Professor Setunge and her team at the Bushfire and Natural Hazards CRC are looking into the role natural hazards such as floods and extreme rainfall might have on the likelihood bridge collapse in Australia. They have already found that failure of some of the bridges during the 2010-2011 Queensland floods could have been avoided if the vulnerability of the bridge had been assessed prior.
“We have also identified all critical bridges in Victoria and are developing vulnerability models to demonstrate the likelihood of failure of the bridges under extreme natural hazards,” she said. “This needs to be expanded to all states of Australia.”
Read the full AusSMC reaction here