Adebar’s experiments set the wheels in motion to change Canada’s building codes. But the process will take years and won’t do anything to improve existing high-rises. Now Adebar is examining the engineering plans for 350 buildings in Vancouver to figure out how many are at serious risk from thin walls and other design flaws. The provincial government has undertaken similar studies for schools and public structures, but nobody in British Columbia—or Washington or Oregon—is scrutinizing the privately owned high-rises where so many people live and work.
“You’ve got people with million-dollar condos who have no idea the building they live in is very susceptible to being damaged or potentially collapsing in an earthquake,” Adebar said. “There’s no process to say, ‘This is a bad building.’ ” Condo owners, apartment dwellers, and businesses assume that if anything was wrong with their buildings, the government would take action. But the only time most jurisdictions inspect or require seismic upgrades on existing buildings is when they undergo major renovations or change use. Most owners don’t even know their buildings may be at risk.
Yanev said that’s the main reason he wrote his column for The New York Times. Practicing engineers aren’t eager to talk publicly about problems with buildings they or their colleagues may have worked on. Nearing retirement, Yanev doesn’t care. “I have the liberty of seeing the big picture and not worrying about what clients think.” After visiting so many scenes of death and destruction around the world, he’s got no stomach to see them repeated in his own country. If building owners and others in the Pacific Northwest start pushing now to reevaluate and strengthen dangerous buildings of all types, the region will be much safer when the next big one hits. “What I’m saying is, ‘Hey, guys. Some of these buildings are going to collapse unless we do something about it.’ ”
The most dangerous structures in Portland, Seattle, Vancouver, and scores of smaller cities across the Northwest are concrete buildings constructed before the mid-1970s. Engineers call them nonductile, which means they can’t bend without breaking. Their columns lack enough steel reinforcement to keep them from collapsing in a major shake. And when heavy concrete buildings collapse, it can be deadly to anyone trapped inside.
“Those are the buildings that would probably have the highest casualty rate,” said Cale Ash, of Degenkolb Engineers in Seattle. “If the columns are overloaded and they start to fail, you could see pancaking.” Ash was touring the city’s Sodo neighborhood in the fall of 2012, pointing out buildings that probably won’t fare well next time the ground starts shaking. He pulled his sedan to a stop in front of a likely suspect, a six-story white building.
Recently returned from an earthquake reconnaissance trip to Christchurch, Ash looks at structures like this one with a more pressing sense of concern. It’s often hard to tell from the street which buildings have concrete frames and which of those fall into the high-risk category. The building on First Avenue offers a few clues. The walls still show the marks of the old-fashioned lumber formwork used to cast the concrete. There’s a good chance the building also sits on deteriorating wood pilings, Ash said. The ground floor is taller and more open than the upper floors, which further erodes the building’s seismic prospects.
In his book Peace of Mind in Earthquake Country, Yanev offered a blunt assessment of this type of building: “If you live or work in a pre-1973 un-retrofitted concrete frame structure … you are exposing yourself to one of the greatest hazards in earthquake country.” His advice: Lobby your landlord to upgrade, or move. But if it’s hard for a professional engineer to pick out the most dangerous buildings, it’s impossible for the average person. The building’s age is the best indicator, but some older buildings are better designed than others. “To know for sure, you really have to look at the drawings and study the construction details,” Ash said.
With an estimated forty thousand old concrete buildings across the state, some California cities are compiling inventories and inching toward retrofit requirements. But upgrades can be very costly. There’s no similar effort in the Northwest.
The region is also trailing California in tackling the risk posed by old brick buildings, Ash said, driving past rows of masonry warehouses and former factories built in the early 1900s. The only good thing about the structures from a seismic perspective is that they’re generally smaller than old concrete buildings so they won’t harm as many people when they collapse. Cities like San Francisco and Los Angeles began requiring seismic upgrades on old brick buildings decades ago. Most have been retrofitted or torn down. Some cities post warning signs on those that remain.
In the Northwest, Seattle is leading the way—very slowly—on efforts to mandate retrofits. After several false starts, the city published an inventory that lists more than 800 potentially dangerous brick buildings. Estimates for the State of Oregon range up to ten thousand, with nearly two thousand in Portland alone. A survey in Vancouver identified 8,000 buildings, mostly brick, at risk of catastrophic damage.
Seattle’s brick architecture ranges from low-slung mom-and-pop grocery stores to seven-story apartment complexes with ornate parapets and a hundred or more residents. The greatest density is in the historic Pioneer Square neighborhood and the gentrifying industrial center to the south, where Ash pulled up in front of a handsome specimen. The six-story building dates from 1910, but it’s clearly been spruced up and houses an artisan soft drink company. “There’s diagonal bracing,” Ash said, pointing out angled steel beams visible through the lobby windows. If they’re sturdy enough, the braces should prevent the vulnerable ground floor from collapsing. Horizontal rows of metal rosettes on the front and back of the building indicate the walls were bolted to the floors to keep them from peeling away during an earthquake.
People who live and work in brick buildings can tell if the structures have been retrofitted by looking for braces and rosettes, Ash said. They can also use the city’s list as a starting point. But not all retrofits are created equal. Sometimes a row of rosettes just means the floors were sagging so much that the owner was forced to cinch them to the walls. That might be better than nothing, but it’s not a seismic retrofit.
Regulations require at least a basic upgrade only when old buildings change use or are significantly remodeled. The new mandate the city is aiming for would phase in the requirement for all brick buildings. A basic retrofit doesn’t bring a building up to current seismic standards, Ash explained, but should strengthen the structure enough to prevent collapse in a moderate earthquake. It also reduces the danger of bricks falling on passersby and parked cars.
There’s no guarantee a building with a bare-bones retrofit will survive a more powerful quake. But Ash likes to show photos of two nearly identical brick buildings from Christchurch, just a block apart. The building that hadn’t been retrofitted was in ruins. The one that had was still standing, with minimal damage.
Less than half a mile from the soft drink company on First Avenue sits an example of the third type of building no engineer wants be caught in during an earthquake: a concrete tilt-up warehouse. This one is a big-box hardware store. Tilt-ups are common because they go up quickly. Wall segments are poured in place atop a concrete slab, then tilted up into position. If the connections between the wall segments and the roof are weak, the walls can fall like a house of cards.
The good news is that codes have been ratcheted up several times since the mid-1970s. The bad news is that the changes were necessary because tilt-ups seem to get crunched in every major earthquake. The collapse risk isn’t high for the newest versions, but the potential for damage is. “So these buildings that have all our food and our home repair supplies could be red-tagged after an earthquake,” Ash said, “when you need them the most.”
Under Seattle’s Aurora Bridge, Carl Barker cocked his head and listened to the whomp-whomp-whomp of traffic speeding by more than 150 feet above. The bridge was getting a seismic retrofit, and Barker could already hear the difference in its vibrato. “It’s just a feeling,”
he said, groping to describe a special sense developed over decades as an engineer for the Washington State Department of Transportation. “I can tell it’s stiffer.”
Opened in 1932, the bridge arches gracefully over the Lake Washington Ship Canal. Every day almost eighty thousand cars cross the critical link on Highway 99. When crews dug out the abutment at the bridge’s south end, they discovered cracks in both girders, probably from previous quakes. Laboratory tests on mock-ups of the aging concrete columns didn’t bode well for performance in the next big shake.
As part of the $12.4 million retrofit, the bridge got new expansion joints that allow sections of the deck to slide past each other by more than a foot. Crews sawed through several massive concrete supports and installed shock-absorbing bearings. They excavated around the bridge’s footings and added tons of additional concrete. Barker pointed out green-and-black wrappings on several columns. These reinforcing layers are the same type of carbon fiber Boeing uses on the 787 Dreamliner.
The bridge is a historic landmark, so the fixes were designed to blend seamlessly with the original design, Barker explained on a cool day in October 2012. When crews were bolstering the north end, they had to take special care not to damage or block access to the Fremont Troll, a concrete ogre hunkered down with a Volkswagen in its grip.
Barker is satisfied the improvements will do the job. “The bridge shouldn’t fall down,” he said. But there are five hundred others across Washington that could, and at least that many more in Oregon and British Columbia. The Oregon Department of Transportation (ODOT) says that every bridge connecting the I-5 corridor to the coast is likely to collapse in a Cascadia megaquake, leaving tsunami-ravaged communities cut off from help. In Portland, nine bridges that cross the Willamette River—including the I-405 bridge—were built before modern seismic codes and only a handful have been retrofitted. The most optimistic observation in ODOT’s 2009 analysis is that a few segments of I-5 would probably remain passable.
Power, gas, water, and sewer lines are even less equipped than roads and bridges to survive strong shaking. Several high-power transmission lines run through industrial tide flats across the region, where the ground could shift twenty feet or more. Substation transformers that aren’t bolted down will be knocked off their foundations.
Many water and sewer lines in the Northwest are buried in river valleys where shaking will turn the ground to jelly. There are still no seismic design requirements for new lines. In Japan, where gas lines are equipped with their own seismometers and automatic shutoff valves, it took three months and the efforts of four thousand extra workers to bring Sendai’s service back to full capacity after the 2011 megaquake. “I compare that to what we have here, and I know we have big trouble ahead,” said Yumei Wang, geohazards team leader for the Oregon Department of Geology and Mineral Industries.
Wang recently surveyed the tank farms and pipelines that store and deliver 90 percent of Oregon’s liquid fuels, from gasoline and diesel to jet fuel. They’re all clustered by the Willamette River on the shakiest ground possible. Portland International Airport’s only fuel supply arrives via one of those pipelines. “All our eggs are in one basket,” she said.
The fact that Wang and others are identifying weaknesses and starting to address them is a remarkable turnaround for a region where emergency managers’ worst nightmare used to be a flood. Jim Mullen took over Seattle’s emergency department in the early 1990s. As he learned more about seismic hazards, he would pile his staff into the car every Friday to cruise the city and brainstorm scenarios. “We looked at the structures we had and talked about the vulnerability,” recalled Mullen, who went on to direct the Washington State Emergency Management Division for nearly ten years. “For me, that was the ‘oh shit’ moment.”
Mullen realized the city didn’t have a clue about how to deal with powerful quakes. “We were totally unprepared. Our plans were godawful.” Early earthquake drills dissolved into bickering among city departments. In the late 1990s a FEMA-funded program called Project Impact helped get the region moving with enough federal funding to identify problems and get some of the fixes started.
Washington’s transportation department was an early adopter. Since 1991 the agency has at least partially retrofitted about four hundred vulnerable bridges, welding steel jackets onto concrete columns and bolting down the decks. The agency’s top priority is to create an earthquake resilient route through the Puget Sound corridor. After years of political gridlock, in 2011 the state began dismantling Seattle’s decrepit Alaskan Way Viaduct—before the collapse depicted in WSDOT’s earthquake animation could come true.
Seattle voters passed a $365 million levy in 2006 that included funding for retrofits on several bridges. Money from another levy is upgrading fire stations so first responders won’t be trapped inside damaged buildings. The city strengthened water towers and hardened several fire hydrants to stand up to intense ground shaking. Firefighters also have new pumps and hoses that allow them to pull water directly from lakes, reservoirs, and Puget Sound.
Resilience is the new buzzword in disaster response. It’s one thing to survive the immediate crisis but another to bounce back from a blow that could send the entire region into an economic tailspin. Nobody wants to be the next Kobe. The Japanese city was one of the world’s largest container ports when it was hit by a shallow magnitude 6.8 earthquake in 1995. Nearly six thousand people died. Rail lines were knocked out and major expressways weren’t fully reopened until twenty months later. Some analysts cite the quake as one of the factors that pushed Japan into a decade of decline.
Both Washington and Oregon have embarked on resilience planning. Without those efforts, a Cascadia megaquake could kick off a downward spiral, warned a 2013 Oregon report. “A policy of business as usual implies a post-earthquake future that could consist of decades of economic and population decline—in effect, a lost generation that will devastate our state and … affect the regional and national economy,” the report concluded.
It’s impossible to fix everything at once, Wang said, but there’s no better time to start than now. “The scary thing about an earthquake is that it finds the weak links, and it’s merciless. It won’t say ‘I won’t bring that building down because there’s a bunch of kids in there.’ ”
When it comes to earthquake preparedness, there’s no more emotional flashpoint than schools. No parent wants to put a child in harm’s way just by sending him or her off to class. California took that danger to heart nearly eighty years ago. The Long Beach earthquake of 1933 struck on a Friday a few hours after schools had let out. Nearly 250 classroom buildings crumbled or were seriously damaged, and residents shuddered at the close call. Within thirty days the state legislature passed bills requiring earthquake-resistant construction for schools and banning new unreinforced masonry buildings.
School safety in the Northwest remains largely a function of political boundaries. British Columbia launched seismic upgrades more than a decade ago and has committed $1.5 billion to the effort. Half the public schools in Oregon are rated at a high or very high risk of collapse, and the state is only slowly making upgrades. With voter support for levies, the Seattle School District had worked its way through about two-thirds of its dangerous buildings by 2012. Washington has yet to conduct a statewide seismic survey of schools.
The Northwest also falls behind California in grappling with the problem of earthquakes that rip the surface of the ground. In 1971 the San Fernando quake opened a ten-mile-long gash across Southern California and tore apart homes and commercial buildings. Governor Ronald Reagan signed the Alquist-Priolo Act into law the next year, restricting construction near known fault scarps. The law also requires the state to map fault zones, which is fairly easy in California. In the Northwest, it wasn’t until the late 1990s that lidar started to peer through the trees and pick out the scarps hidden below.
When Washington’s most populous county decided to build a new sewage treatment plant fifteen miles northeas
t of Seattle in the early 2000s, the hazard posed by surface faults in the Northwest wasn’t well-understood. Nobody wants sewage ponds in their backyards, so it took a bruising battle to settle on a location. County officials weren’t about to start over, even when USGS scientists cleared their throats and pointed to three places on the property where earthquakes on the South Whidbey Island Fault had broken the surface.
The county commissioned the USGS to excavate one of the scarps, where the scientists found evidence of at least three quakes. As the cost of the project soared to $1.8 billion, engineers seismically strengthened the plant and hoped for the best. So one of the state’s costliest public investments now sits on top of the region’s biggest shallow fault.
The power of engineering to overcome suspect terrain in the Pacific Northwest was put to its greatest test with the construction of Seattle’s two professional sports stadiums. Safeco Field, home of the Seattle Mariners, and CenturyLink Field, where Seahawks fans raise such a din it registers on seismometers, sit side by side on land that didn’t exist a hundred years ago.
Photographs from the early 1900s show a broad lagoon fringed by mudflats. Trains chugged across the water on elevated trestles, moving coal, timber, and sacks of flour between mills and ships anchored offshore. When the city decided to level its steep hills, workers sluiced tons of excavated dirt into the lagoon. They tossed in tree stumps, too, along with trash, building debris, and anything else they could lay their hands on. When they were done, the city’s waterfront was extended southward by several square miles. The new ground was flat, perfect for building—and about the last place a seismic engineer today would choose for arenas that collectively hold more than one hundred thousand people.
Full-Rip 9.0: The Next Big Earthquake in the Pacific Northwest Page 22
