I tried to write this post four weeks ago but the words weren’t flowing. After three weeks of earthquake damage assessments in Christchurch it feels good to finally be back in Wellington. I was getting tired of living out of a suitcase. Dad laughed at that statement given that I lived out of a van for so long. Ironic, I suppose, but the difference is that Christchurch is a boring place and boredom is self-inflicted when mobility is at your disposal. It also wasn’t helping the cause that I’m just starting to put together a social life in Wellington. More on that another day.
My work in Christchurch, however, was very interesting. Some of the other structural engineers and I were sent down to Christchurch to perform damage assessments on behalf of a damage assessment firm that consults for insurance companies. That’s right, I was consulting for consultants—the hallmark of a modern economy. My assigned buildings ranged from single family homes to churches to moderately large commercial and industrial structures. I got to inspect wood, brick, concrete block, cast in-place concrete, tilt-up precast panels, steel and glu-lam portal frames and more than a 120 years of construction methodologies. Our job was to meet with an owner or tenant and walk through the scheduled structure with a critical eye. I would look for obvious and subtle signs of damage like cracked drywall, masonry or concrete; skewed doorways; slanted, spongy or bouncy floors; leaning chimneys or buttresses; cracked or buckled beams and columns; or loosened bracing members. The cumulative damage was considered and translated to a 2-page report to the client which provided a brief explanation of the repairs required to fix and strengthen the structure or if it should be written-off. That 2-page report represented tens—if not hundreds—of thousands of dollars in decision-making. The experience was invaluable and I’m really glad I got tabbed to take part.
Three things can be taken from the earthquake, all three related. First, as a profession,
structural engineers are not entirely full of shit. Hooray! Most buildings suffered superficial cracks at the worst and of the ones badly damaged, those were either built on crappy foundations or were old and run-down. The obviously at-risk buildings were mostly ratty beach shacks or a motley patchwork of brick buildings that have seen many renovations but few structural improvements. Any lay-person could have identified them as the most likely to be damaged in an earthquake.
So how did we engineers do a good job? The current manner of designing structures is a prescriptive process where location, building type, building material, anticipated lifespan of the building, and a handful of other parameters are used to determine the baseline forces. The structure is then designed to be strong enough to handle these forces with a factor of safety left over. Of the parameters, the most theoretical is the design response spectrum. It is a series of curves based on the natural period of the structure and an envelope of probable peak ground accelerations for a really large earthquake. I would explain more but the description is really long and complicated without using pictures and my dear readers would start falling asleep. It’s a highly scientific guess at a completely unpredictable event based on historical data. Because of the
diligent work of a couple of NZ seismologists, a lot of small, cheap seismographs were installed in the Canterbury region over the last 5 years.
The data they gathered confirmed the design response envelope--mostly. In other words, engineers made a bold prediction about the nature of earthquakes and got the building code to fit that prediction. When a major earthquake struck, not only was the prediction proven mostly correct, but buildings then performed as planned if not better.
Second, the NZ government was excellent. Amazing even. When the earthquake struck, the local civil defense volunteers jumped into action to establish lines of communication and sweep neighborhoods looking for people needing assistance. The Canterbury regional governments were quick to set up provisional rules for governing post-earthquake with the intention of getting life back to normal as quickly as possible. One of the homes I assessed was in the beach town of Brooklands, an area heavily affected by soil liquefaction. Driving down the main road, the sewer manholes were all sticking above the surface of the street by a foot for as far as one could see. The sewer line had become buoyant and popped to the surface like a giant game of whack-a-mole. Because sewer lines use gravity for flow and not pressure (like water), the angle of fall down the line is critical to keeping things moving. In becoming buoyant, the angle of fall is affected either between homes and the main line or down the line itself. Basically, the whole line was ruined and needs to be replaced. Residents could no longer flush their toilets and water down the drains was coming out of a broken pipe somewhere between the houses and the sewer line. In response, the regional government had portable toilets set up on every block. Damage to utility lines was common in neighborhoods where liquefaction was widespread, but in every case I was aware of the government was active in setting up temporary facilities and implementing a plan for repairs. This would be a daunting task in normal times but when the entire region is competing for resources it takes a balanced hand to care for all without neglecting individuals. The Canterbury regional governments were doing an impressive job of acting exactly like a government should.
Further up the government chain is the Earthquake Commission. The EQC is a government slush fund for natural disasters maintained by a small levy on property insurance. Surprisingly, the NZ government has been sitting on this money since the fund was established in 1945. Unlike the American government (in all of its forms), the NZ government has been responsible enough to maintain the fund integrity and invest it in fixed interest securities and conservative equity funds instead of raiding it like a piggy bank and leaving worthless IOUs.
The EQC serves many functions. The assessment wing does a quick check on any structure (insured or not) giving them a green, yellow or red sticker to signify safety and accessibility. Secondarily, for those with insurance, the EQC provides short term financial assistance to people displaced from their homes by red stickers. The third function is as disaster insurance. The commission designates up to NZ$100,000 per structure depending on damage and pre-disaster value. This fund is the primary payout and any private insurance claims are for damage beyond the initial NZ$100,000. Because of this, insurance rates for Kiwis are kept low. Most importantly, while an insurance company may fight paying out on a claim, the EQC has an expressed interest in paying out and seeks to facilitate the rebuilding of the community. We were hearing that EQC claims were being processed quickly and not once did I hear of anyone who felt screwed by it.
The government was becoming a victim of its own efficiency. During the last week I was in Christchurch, there were several reports of local towns complaining that their utilities hadn’t been restored fast enough. How quickly people lose perspective on the magnitude of the events that surround them.
Lastly, this event marks a new era of purely financial disasters. The death toll was zero. The notable casualties numbered 1. One. Uno. A guy had his foot smashed in falling debris in his home and it had to be partially amputated. That’s the extent of the human toll. When I arrived, it was two weeks after the initial event and the prevailing sentiment was of a community uniting as neighbors and by the fourth week people were bitching and moaning about the slow pace of water line repairs. It’s not that they stopped caring for their neighbors, but that everyone realized life would go on with very few changes from before. Most people will have to deal with a few temporary traffic detours, the loss of a café near their office or need some cracked drywall repaired. Those who suffered the most lost their homes. I don’t mean to belittle these losses because it would be emotional and sad and frustrating to be one of the unlucky few but no one in Canterbury is mourning the loss of family or friends. 220,000 died in Haiti and another 300,000 were injured and a million displaced. The Pakistani Floods earlier this year killed 2,000 and injured or displaced another 20 million. The Indonesian Earthquake and Tsunami of 2004 killed some 250,000 people, injured another 149,000 and displaced nearly 1.7 million people. These are just some of the terrible natural disasters that have devastated places in the past decade. We learned long ago that most natural disasters are unavoidable and unpredictable, but nearly a century of valuable scientific and engineering research have taught us how to manage the risks to minimize loss. In the case of the modern, western economy, people's lives have become so valuable that any death is unacceptable. Somewhere Adam Smith is screaming "I told you so" but in a funny Scottish accent. I feel weird admitting that my libertarian friends are right. But even they would extoll the performance of the NZ government in this situation.
Admittedly, this wasn't the greatest post but I was anxious to get it done. New adventures are forthcoming. Plus I need to start explaining my office, my (changing) home life and Kiwi culture. I will post more frequently. I promise.
