Fault lines: Do lax seismic standards conceal underlying earthquake risk of Metro Vancouver tower fetish?

Tower under construction in Tokyo Aug 2016b small

Close-up view of girders used in tower construction, Tokyo.

An article entitled “Financial fault lines: The earthquake risk of Vancouver’s condo boom” (The Globe and Mail,  11-Aug-2016) referred to a fresh report (“Fault Lines: Earthquakes, Insurance, and Systemic Financial Risk,” by the C.D. Howe Institute). The emphasis of both items was on financial risk.

That is important, but we look beyond the financial risks to underlying issues in terms of policy, architectural standards, and life safety. This is another “elephant in the room” of Metro Vancouver’s construction boom and all the players in the game are implicated — but CityHallWatch believe the heaviest responsibility is on our mayors and councillors. They are ultimately the ones who approve rezoning and construction projects.

See further below for links and excerpts of the article, but here are some thoughts and observations by CityHallWatch.

  • Natural Resources Canada estimates a one-in-three chance that massive earthquake will hit the West Coast in the next 50 years.
  • The construction industry has been booming, enabled by city councils that have approved many towers in the past ten years, and continue to do so at a record-setting pace.
  • Our opinion is that the construction industry, professional associations, professionals (architects, planners, etc.) and governments (municipal, provincial, and federal) are failing to protect the financial system and public safety, by failing to have world-class seismic safety standards. Ignorance of the risks is no excuse. Blaming others  is no excuse. Each of those entities has a high level of responsibility.
  • In the Lower Mainland of B.C., our mayors and councillors have a moral obligation to pay more attention to the matter of seismic safety.
  • An expert quoted in The Globe and Mail hopes that “maybe 10 years from now, 20 years from now, our building code will have what it takes to guide designers so buildings not only save lives, but are actually usable after an earthquake.” The point being that building codes in Vancouver, in British Columbia, and in Canada are designed only to permit immediate evacuation after an earthquake. Towers are not intended to be usable after even a moderately-sized earthquake.
  • Irregular buildings are probably seismically more dangerous. City Council has been approving them, but are they aware of the risks?
  • Compare this with Japan. Even after the as a magnitude 9.0 (Mw) undersea megathrust earthquake off the coast of Japan in March 2011, only a small proportion of damage to structures resulted from the earthquake (most of the damage was caused by the tsunami). Even smaller structures a few storeys high are often built using steel girders — unlike the reinforced concrete permitted in B.C. for towers even sixty storeys high or more. See photos.
  • One could say that all structures in the Lower Mainland (including unusual new tower designs) are over-valued economically, by the failure to discount for the potential risk of catastrophic building failure in the event of a massive quake. An adjusted valuation for real estate purchases might include a discount for the likelihood that the building will be rendered unusable on a moment’s notice.
  • City planners should think long term with an awareness of seismic risk. Imagine the thousands of people living in new towers. After even a moderate earthquake, their buildings could be rendered useless, or living above the fifth floor might be impractical for long period of time for most people without elevators.
  • There has never been a peer-reviewed academic comparison of seismic standards for tower construction between the world’s best (probably in Japan) and Vancouver or British Columbia. One should be done immediately, and published.

Tower under construction in Tokyo Aug 2016a small

Above photo – Under construction in Tokyo, Japan: Steel girders are used in anything over several storeys high, in contrast to B.C., which uses reinforced concrete.

earthquake seismic graph

References and excerpts of article

Financial fault lines: The earthquake risk of Vancouver’s condo boom
By Alicja Siekierska, The Globe and Mail, 11-Aug-2016. http://www.theglobeandmail.com/real-estate/vancouver/financial-fault-lines-the-earthquake-risk-of-vancouvers-condo-boom/article31354381/

Fault Lines: Earthquakes, Insurance, and Systemic Financial Risk
(C.D. Howe Institute, 3-Aug-2016). Download full report in PDF. https://www.cdhowe.org/public-policy-research/fault-lines-earthquakes-insurance-and-systemic-financial-risk

************

Financial fault lines: The earthquake risk of Vancouver’s condo boom
By Alicja Siekierska, The Globe and Mail,  11-Aug-2016

 

Driven by rising demand for condos amid soaring home prices, a new wave of costly – and often architecturally beautiful – high-rises is transforming the Vancouver skyline. But engineers say what some condo owners can’t see could potentially cost them more than they expected.

Two plates of earth deep below the Pacific’s surface about 100 kilometres off the British Columbia coast are threatening to cause a quake that would likely amount to the worst natural disaster in Canada’s history. According to Natural Resources Canada, there is a one-in-three chance that massive earthquake will hit the West Coast in the next 50 years.

While Vancouver’s skyscrapers adhere to a code designed to safely get people out of buildings in the event of an earthquake, engineers say that some structures could become uninhabitable after a powerful quake strikes.

“The problem is, in my mind, that people are buying condos in these new buildings and don’t realize that,” said Perry Adebar, the head of civil engineering at the University of British Columbia, noting that the less uniform and more irregular the structure of a high-rise building is, the more likely it will be damaged.

“They figure that, surely it’s designed well. To be totally clear, I don’t think anybody realizes it. The more exciting and interesting your building is, the more likely you won’t be able to use it after a significant earthquake.”

… A report from the C.D. Howe Institute released last week [Fault Lines: Earthquakes, Insurance, and Systemic Financial Risk, August 3, 2016] warned that a massive earthquake in British Columbia could create a dire financial scenario in Canada. Insurance industry estimates peg expected losses from such a severe quake in the $75-billion range and some insurers say that number could be even higher.

 

…. The City of Vancouver’s building code is adapted from the provincial code, which is derived from the National Building Code of Canada. Patrick Ryan, the city’s chief building official, says the building code has several provisions around environmental issues, energy, accessibility, fire and life safety, and seismic standards – particularly on how to deal with upgrades and retrofitting – that are unique to Vancouver.

When it comes to seismic provisions, the Vancouver code is meant to protect the lives of the occupants of a building, but does not mean the building will be serviceable after an event, Mr. Ryan said“The code is a minimum,” he said. “You don’t have to follow the minimum. If an owner chooses to overdesign a building, they can do that and there’s no problem with that.”

Vancouver also has an extra provision that requires a designated structural engineer to conduct the design work on larger buildings, including high-rise condos. Those designs are then peer-reviewed by a second engineer to ensure they are sound.

Still, Mr. Adebar says there are misconceptions about the building code.

“There is a huge disconnect between what people think the building code achieves, people’s expectations of how a building code will perform in an earthquake versus what we’re doing when we write the building code and what our expectations are,” he said.

Many buildings in Christchurch, New Zealand, were unusable after a 6.3-magnitude earthquake hit, with an epicentre just 10 kilometres from city, in 2011. That quake offered an important learning experience for Vancouver, says Andy Metten, a managing partner at Bush Bohlman and Partners, an engineering firm in Vancouver.

“Several fairly modern buildings – the Hotel Grand Chancellor for example – had to be demolished after the event. That building was leaning and had significant damage and a lot of that was felt to be due to the irregularity of the building,” said Mr. Metten.

Many buildings that were built quite recently were torn down. The issues are that the buildings with irregularities that are much more attractive from an aesthetic point of view do tend to perform not quite as well as those that are more regular.”

Mr. Adebar, a member of the Standing Committee on Earthquake Design that advises on seismic standards for the building code, says today’s building code does not provide any requirements or guidance on how to design a building so it will be more likely usable after an earthquake. Whether a building will be usable depends on many factors, including soil conditions and the architecture of the building. He says it is difficult for a layperson to distinguish what an irregular building is, and that not every building that appears irregular on the outside is the same internally. Many irregular buildings will be structurally normal on the inside, he says, thanks to good architecture and clever engineering.

“On the other hand, there are buildings that are as irregular internally as they seem externally, and these are the buildings that are much more likely to be damaged during an earthquake,” he explained. Such buildings get built because architects do not appreciate the direct connection between structural irregularity and the likelihood that a building will be damaged during an earthquake, and engineers are constrained to design the building to meet the minimum requirements of the building code.”

 

….Jeff Yathon, a civil engineering PhD candidate at UBC, has spent the last three years analyzing the designs of about 350 mid– and high-rise buildings constructed before 1980 in Vancouver, trying to determine how vulnerable the structures are. While he doesn’t foresee building collapses in the event of a strong earthquake, he says it was slightly concerning that many similar buildings were often clustered in the one area because it is likely that if one is damaged, many will be.

Mr. Adebar hopes that the code continues to improve over the coming decades.

“I don’t know the solutions, at least for the older buildings, but for the new buildings I think there is a solution and it’s one of just everyone becoming aware of what the situation is,” he said. “I don’t know how long it’s going to take, but I think maybe 10 years from now, 20 years from now, our building code will have what it takes to guide designers so buildings not only save lives, but are actually usable after an earthquake.”

Go to The Globe and Mail for the full article:

http://www.theglobeandmail.com/real-estate/vancouver/financial-fault-lines-the-earthquake-risk-of-vancouvers-condo-boom/article31354381/

 

 

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