BC Ferries terminals would collapse and sink in megaquake: Engineer
Posted February 11, 2015 11:11 pm.
This article is more than 5 years old.
VANCOUVER (NEWS1130) – A Vancouver Island engineer says BC Ferries terminals could collapse in the event of a megaquake. His solution is to build floating terminals, a proposal which is being passed onto municipal leaders tonight.
Ray Hebden with Hebden Engineering says in the event of an earthquake larger than magnitude 9.0, ferry terminals could end up destroyed which would be a major problem. “If the ferry services were curtailed for some reason, we would have a tough time, a lot of our food comes by ferry, other goods come by ferry, and almost everything comes by ferry. A very large earthquake could have dire consequences to the two main locations where those ferries take off to the island that is Tsawwassen and Horseshoe Bay.”
He says the Tsawwassen Ferry terminal which sits on alluvial soil is the most susceptible to sinking.
“My understanding of it that at Tsawwassen, you have a lot of the structures on piles, and they’re driven in the soft material by use of a vibration hammer. They gain strength of the material holding on. What happens if the ground shakes for a long period of time then that soil goes to liquid and it can’t support the weight anymore. There’s a great danger that the Tsawwassen ferry terminal would start to sink,” he explains.
He is a part of a group of engineers calling on the crown corporation to put in a few floating terminals like the one built in Swartz Bay in 2006. “What we are proposing, we meaning a four company consortium, we built a berth at Swartz Bay in 2005 and 2006 so it’s been operating since then, It is fully floating, It is a large concrete mass that is held in place by flexible means so that it allows the ground to move in an earthquake and the mass stays inert.”
He says the idea has been pitched to BC Ferries and both the provincial and federal governments, resulting in a lack of support.
Deb Marshall with BC Ferries says an extra floating berth to be on standby in case of a catastrophic earthquake is not necessary and is “awfully expensive.” “It is above our operational needs we don’t have the $20 to $30 million in our capital budget to cover such a cost for such a structure and nor is it within our mandate.
She notes everything at BC Ferries is built to new seismic codes, adding fare affordability is a big issue for BC Ferries’ passengers and the crown corporation has to watch every dollar it spends.
