Engineering experts recently spoke about resilience and how B.C. is preparing for inevitable seismic events that could threaten its infrastructure.
The discussion was part of this year’s Transportation Conference organized by B.C.’s Association of Consulting Engineering Companies.
“Resilience is not a new concept,” said Carlos Ventura, director of the Earthquake Engineering Research Facility at the University of British Columbia. “It was in fact developed in the 19th century as an engineering concept to determine the capacity of wood structures.”
Ventura noted now engineers have much more sophisticated ways of measuring resilience, which he likened to an athlete. If that athlete becomes injured, their ability to recover depends on how well prepared they were and their age.
“We define it as the ability to bounce or spring back into shape, position, etc., after being pressed or stretched,” he said.
He explained key elements of resilience are the time to recover, how fast we can recover fully and what level of we can achieve to continue residual functions.
“What is our motivation? We want to prevent a disaster from becoming a catastrophe,” he said. “We must accept that we cannot prevent every risk from being realized but rather we must learn to adapt and mange risks in a way that minimizes impact and focuses our efforts on critical infrastructure.”
Ventura explained critical infrastructure is related to key systems, services and functions whose disruption or destruction would have a debilitating impact on public health and safety, commerce and national security. This includes communications, energy, banking and, of course, transportation networks.
“If one of those things does not function during an event, resilience is not achieved because these systems all depend on each other,” he said.
Ventura stressed there is a huge financial incentive to think about resilience now. The Federal Emergency Management Agency (FEMA) in the U.S. reported their research shows there is $6 to $10 saved in post-earthquake losses for every $1 invested in seismic upgrades.
Alireza Ahmadnia, the Ministry of Transportation’s senior seismic and structural health engineer, spoke about what investments the province is making and where it decides to spend. He explained the province’s 47,000 kilometres of provincial highways and rural side roads, more than 2,800 bridges, 900 large culverts and 1,300 large retaining walls are in a region of the world with unique seismic activity.
“There are three features of resilience that transportation infrastructure should have,” Said Ahmadnia. “Reducing probability of collapse, reducing consequences and reduced time to recovery. If you have that you can say your transportation is resilient.”
To achieve this, you need the four “R’s” of resilience: Robustness (being strong enough to withstand demands without losing function), redundancy (having a system with alternative options), resourcefulness (capability to mobilize resources) and rapidity (how fast disruptions can be overcome and repaired).
The seismic program is working to create a standardized, modern design code for transportation infrastructure and retrofit bridges. Of the 500 bridges that are seismically vulnerable, 200 have been replaced or retrofitted, started with bridges that are critical routes in and out of major population centres. The ministry is also looking back at major bridges that have been upgraded or replaced to determine if they meet today’s seismic risks.
“We are looking back at our lifeline structures, like Second Narrows, Lions Gate Bridge, Oak Street Bridge to see how they are performing,” he said.
The province has also revamped some of its post-earthquake response plans with modern technology, including a phone app to streamline asset inspections.
“We know that after the earthquake there will be lots of assets that need to be inspected and its very difficult to collate all this information and send it to one centre,” he said, noting the system was used successfully during the recent flood events that damaged significant sections of the transportation network.
Don Kennedy, vice-president of transportation structures at Associated Engineering, explained another major project is the Highway 99 corridor resilience study which seeks to identify and understand seismic vulnerabilities and risks in the network.
“The project is treating it as a system rather than individual assets,” he said, adding the project will work with experts at UBC and use technology from the U.S.
The result will be a deeper, more holistic understanding of how earthquakes could impact the corridor and how the process could be applied to other corridors.
Russell Hixson is the staff writer for the Journal of Commerce where he covers the construction industry. Before that, he spent years in the U.S. as an investigative crime reporter. He lives in East Vancouver. Follow him on Twitter: @RussellReports.
