If February’s quake in Christchurch, New Zealand didn’t grab enough attention, the utter devastation in northeast Japan after the big one hit March 11 has prompted some questions from politicians.
What would happen if a big earthquake hit the Lower Mainland and the bridges to Maple Ridge and Pitt Meadows were knocked out? asked Maple Ridge Coun. Al Hogarth.
“How self-sufficient we could be … being able to function as a community and meet the needs of our constituents, where the links are cut?”
Hogarth wanted to know after council was given an update on emergency response at its Monday meeting.
He also wondered if people would be as stoic as the Japanese and feared riots could break out from homeless, hungry people.
“If the worst happens here, don’t necessarily expect that the hands-on people are going to be there hand feeding you. It’s really talking about self-sufficiency.”
While people are encouraged to be able to last 72 hours after a quake without outside help, that period of time could stretch for weeks.
Under the Emergency Program Act, local governments have to have emergency response plans and practise them.
“We’ve got to make sure we’re self-sufficient,” added Coun. Craig Speirs.
But Coun. Cheryl Ashlie pointed out that Maple Ridge’s generosity in helping others in time of need could be turned inward and that it, too, could survive or cope with a disaster.
Ceri Marlo, who manages the emergency program in Maple Ridge, said the district will be more pro-active in its public education programs and says the number of inquiries about emergency preparedness have increased in the week after the Japanese tragedy.
If the Golden Ears or Pitt River bridges were knocked down, Maple Ridge would have to rely on boats to cross the Fraser and Pitt rivers.
“It would be like Dunkirk, or something,” commented Coun. Linda King.
(Dunkirk involved private British boat owners who evacuated stranded troops from France during the Second World War.)
That’s a scenario, but an unlikely one, that’s covered in emergency planning. Marlo said mustering stations have been identified along the Fraser River where authorities could use boats, most likely requisitioned from private owners, in order to cross the Fraser River.
Two locations, one at Queenship ship building operation in east Maple Ridge and another at the Pitt Meadows Regional Airport, have already been identified for such purposes.
But it’s unlikely it would come to that, no matter what kind of earthquake rocked B.C.
Both the Pitt River and Golden Ears bridges have been built to withstand major quakes an the Mission Bridge is currently being retrofitted for the same purpose.
According to Kevin Baskin, chief bridge engineer with the Ministry of Transportation and Infrastructure, the new Pitt River Bridge could take a quake that’s estimated to strike only once every 475 years, equivalent to a Magnitude 6-7 – and still be open to traffic.
“For that level of earthquake we designed the structure to be open,” Baskin said.
Traffic could drive across the bridge after such an event.
The Pitt bridge, along with the Port Mann Bridge, even could withstand a quake that’s estimated to strike only once in every 2,475 years, equivalent to a Magnitude 6 to 9 quake, and still be standing.
“That’s designed based on the collapse-prevention level of performance,” Baskin said.
While the bridge may be damaged, it shouldn’t fall down and imperil those on or beneath the bridge.
“We start by making sure that the foundations are not going to be affected by the shaking.”
For the Golden Ears Bridge, after a major quake hit, there would be only a five per cent chance of the bridge closing temporarily and a one per cent chance of it closing altogether.
“It would have to be a big one to get to that point,” said TransLink spokesman Drew Snider.
Baskin said seismic strengthening is done by ensuring all the components, the deck, the towers and the pilings of the bridge are securely fastened together so they don’t fall apart under shaking. Concrete components, such as pillars or foundations, are also strengthened by encasing them in steel so they don’t crumble during a quake.
Mission Bridge also is being retrofitted by strengthening the connections between girders and the foundation and by wrapping concrete pillars in either steel or fibre to prevent crumbling. That $10-million project is currently underway and will be followed by a second phase in which the ground beneath the bridge will be stabilized. However, those measures will only ensure the bridge doesn’t collapse during a one-in-475-year earthquake.
• Maple Ridge regularly conducts emergency planning exercises to test its response. In 2004, it scripted a flood scenario and in 2005, tested out response to a wildfire. A simulated rail disaster was done in 2006 and a new simulated disaster will be done this fall.
Officials meet monthly. “We have quite an advanced program,” Marlo said.
In response, Maple Ridge is hosting a public emergency preparedness seminar in a few weeks, open to anyone.