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Engineering News

Thursday, 02 April 2015

Who’s responsible when a bridge falls down?

Who’s responsible when a bridge falls down?

Rudolph Kotze had two graphic examples to demonstrate his point that monitoring the condition of bridges is a life and death issue.

At his presentation to the Transport and Infrastructure Forum as part of Engineers Australia Convention 2014, he showed pictures of two bridges that collapsed – one in Canada, the other in the US – killing 17 people in all.

Despite both bridges having flaws in them dating back to when they were built, investigating authorities laid blame at the asset owners for not keeping an eye on things.

“I think this is a question anybody involved with asset management – particularly bridges – right from the inspector to the board, should ask themselves: ‘How comfortable are you and what are the risks facing our infrastructure?’ ” he said.

“What stands between the opening ceremony (of a bridge) and demolition is asset management, that’s what I’m talking about.”

Kotze is the National Technical Leader, Bridges and Structures, with the ARRB Group.

“Risk management is a simple process. You identify it, you assess it, you decide what you need to do – how can you mitigate those risks – and monitor things,” he said.

But things can get tricky. For instance, he showed a bridge in New Zealand made from Australian hardwood that had obviously seen better days.

“A young engineer would condemn that bridge, you need experienced engineers to do this because that bridge carries fully laden coal trucks twice a day, without a problem,” he said.

“So you need to get engineers onboard who have experience.”

Kotze said one of the biggest causes of bridge failures is scour, not earthquakes or other factors.

“We know that, you know that. So you need to make sure your systems look at that. And if they need underwater inspections, you better make sure you do them,” he said.

“I’m not trying to scare you, this is reality.”

He said the key to successful asset management of bridges is knowledge and understanding the risks, and even getting more engineers back working for councils.

“I would really urge councils, jurisdictions, to make sure they retain technical expertise to be able to make these decisions and take these risks on board,” Kotze said.

“You cannot expect your consultant to take liability for your existing assets.

“We have to have a systematic approach that is defendable and we have to document this.

“We need risk profiles and a rational risk-based prioritisation of funding. The only way we can create value for money is to spend the money where it’s needed.”

While the fundamental role of bridges hasn't changed, the sophistication of their planning and construction most certainly has. Engineering Education Australia's (EEA)  Bridge Condition Assessment and Performance Monitoring course will enhance your understanding of condition surveys and structural health. Register today.