The 6.3-magnitude earthquake that devastated the major New Zealand city of Christchurch on Tuesday, Feb. 22, took at least 163 lives and severely damaged much of the city's critical infrastructure. Dr. Roberto T. Leon, professor of structural engineering, mechanics and materials in the School of Civil and Environmental Engineering, was in Christchurch for a teaching fellowship at the University of Canterbury. He arrived one week prior to the earthquake and wrote a special report for ASCE about his experience and how he helped size-up the damage.
Dear friends and colleagues,
First of all, thanks to all of you who have written asking about my safety and wishing me well. It has been an interesting last few days here in Christchurch. I had arrived last Wednesday (Feb. 15) to teach for three months at the University of Canterbury (UC) as part of their Erskine Fellowship program. As many of you know, UC has had a long tradition of pioneering earthquake engineering research, and I was interested in developing collaborations with them in the area of composite structures. Dr. Greg MacRae is my official host here. In addition, I was interested in teaching in the “English” system and finding out how their structural engineering education differs from ours.
I have a small house near the university in the Riccarton area, about three miles east of downtown; my commute to the office is about two minutes walking, which also fulfill one of my requirements for this leave – to get away from my commute in Atlanta. My house is immediately to the west of the Academic Motor Lodge hotel for those of you Google Earth users. I spent Wednesday through Friday getting settled in and preparing lectures, as classes started the following Monday. I am teaching a third-year professional course in advanced structural analysis. I will be doing a short review of the stiffness method and then getting into structural dynamics for multi-degree of freedom systems.
On Saturday, I went for a long walk from the university to downtown Christchurch. The walk took me past Hagley Park and the beautiful Botanical Garden into the Arts Centre and Cathedral Square areas, which are the heart of the city. Part of the cathedral was being used for a famous flower show, but since my wife was coming in a couple of weeks (she still is), I decided not to go inside and wait to go with her when she arrives. I saw much work still in progress trying to retrofit older unreinforced masonry (URM) structures that had been damaged in last September’s earthquakes, as well as a number of them that seemed beyond repair and were waiting for demolition. The day was warm and sunny, there were thousands of people downtown, the cafes and many art galleries were full, and the city gave the distinct impression of being on a strong rebound from its previous disaster. I spent the evening at a barbecue at Greg’s house in West Melton, where his wonderful family, including four young sons, keep goats and other animals.
On Sunday, I took a couple of long bus rides around the town to get a feel of the land. Christchurch has excellent public transportation. Three things impressed me: first, how flat it is (which means that bicycles are an ideal mode of transportation), second, how much pride people take in their houses and neighborhoods (beautiful lawns and flowers everywhere); and third, how outdoorsy New Zealanders are – there are lots of large, beautiful parks and all kinds of recreational sports are played. I made it to the beach at New Brighton at low tide, which meant that you could see how shallow the beach is and how strong the wind and sea currents are most of the time. The day concluded with another outstanding barbecue at Andy Buchanan’s house in the hills south of the city, where I got to meet more faculty, their families and graduate students.
Monday, the first day of classes, was a whirlwind. I thought that I would be teaching a relatively small class (20 or so), but more than 55 showed up to the first lecture. As in the U.S., the students shop around for courses during the first week. I thought it went well when only one student walked out during the lecture! I have benefitted greatly from the mentoring of Dr. Alan Carr who normally teaches the course and is headed to the ROSE School at Pavia, Italy, for the next month or so. Another important highlight of Monday, as it turned out, was the safety briefing that I received from the administrator in CE and his safety officer. It was clear that the University had seriously considered emergencies and had clear plans for what to do.
Tuesday began more quietly and I spent the morning trying to sort out issues related to the course and other administrative tasks. Around 12:30 p.m., I went to lunch with Dr. Say Kee Ong, a colleague from Iowa State with whom I share an office. There are numerous cafes at the university that serve quick meals and we headed to one nearby. We had just sat down to lunch when the earthquake struck.
It was eerily different for me because my most recent recollections are from the large Chilean earthquakes that I experienced last year. The Chilean ones “build up” slowly and last a very long time. This one seemed to be three or four very sudden, violent jerks, with a strong vertical feel, and lasting probably no more than 15 seconds or so. The noise was deafening and I was out the door and outside before Say Kee knew what was happening. The students and staff poured out of the buildings and began to congregate in designated open spots well away from the center of the campus. Most of them seemed relatively calm but as they began to find each other, many of them were clearly very emotional, reliving the events of the previous September.
From the start, everyone that I spoke with said that this event was much bigger than the September 2010 event. There was little time to move away from buildings before a number of large aftershocks occurred. As usual with this type of event, there were lots of aftershocks, to the point where it was hard to tell when the earth was not shaking. However, there were few if any visible signs of damage to university buildings, so the extent of the damage downtown surprised many as the news began to pour in through cell phone conversations. Telephones and text messages became the immediate means of communication, and lines were jammed until people realized that they only should send text messages and leave the phone for emergency operations. I was able to text my wife and children in the U.S. within the hour to let them know I was OK. The university was evacuated and we were told to go home and wait there for further instructions.
Almost immediately the news from the events downtown began to filter out, and I began to walk there (about an hour walk from where I live to Cathedral Square) to see if I could see some of it. As I walked through the adjacent neighborhoods, there was little evidence of damage except for a couple of collapsed chimneys and low walls. However, there was massive evidence of local liquefaction, with sandy water pouring out of most manholes, at the pavement joints, around telephone poles, in the gardens, and in the dark, silty waters of the creeks which had been pristine and transparent when I had seen them Saturday. Obviously much liquefaction must have occurred underneath foundations, but the extent of that damage was not easy to see early on. The golf course at Hagley Park had turned into a series of huge sand traps and ponds, but aside from one collapse of an older bookstore just at the edge of the park, there was little evidence of serious structural damage to the west of the park. I walked by the main hospital which was undamaged; it appeared to be fully functional with many casualties receiving care and walking out from the emergency ward. In addition, helicopters were ferrying the injured, and additional landing areas for them were being setup for them.
Entering downtown from the south side, it was clear than many of the URM buildings had not survived; many had lost their facades, showed large shear cracking, and lost many walls to out-of-plane collapses. The more modern reinforced concrete and steel structure seemed to have survived OK, although cracking in non-structural walls and broken windows were everywhere. As I progressed into downtown a major aftershock occurred (this was just before 3 p.m. local time); the noise was deafening, similar to the special effects one hears in movies for tornadoes. It was possible to see some of the taller buildings swaying and cornices and other non-structural elements falling down. The din of sirens and alarms that began immediately after also made the whole atmosphere more surreal.
There was still some smoke and dust in the air as I was approaching the CTV building area. At that point police began to actively push people out (before then were only pockets that had been sealed) and try as I did, I could not get more than about three blocks to the west of the cathedral – it was painfully obvious from even that distance that the damage to the church and adjacent buildings was disastrous. The beautiful old university neo-gothic buildings that formed the Art Centre, which I had admired on Saturday, had suffered extensive damage, with local collapses in numerous areas. The very modern Art Gallery seemed undamaged from the outside even though it is covered with glass, but the nearby city hall had lost many of its very large windows. As I was being pushed back from downtown, I headed home and made it back to the hotel by about 6:30 p.m. At that point the power was not on, although water service in the area was normal. The crew at the Academy Motor Lodge brought out their grills and cooked for all of us – it was a tremendous gesture given the conditions and I will forever remember the Kiwi hospitality and camaraderie form that night.
Power was restored before sundown so we were able to watch on TV what was going on downtown and south of the city at Littleton and beyond. It was a very tense night with a lot of aftershocks, plus cold and rain to make it even more miserable for everyone.
For the last two days I have been assisting with inspecting buildings at the university. The emphasis downtown until last night was on rescue operations, and they are starting more formal assessments of damage today (Friday) – I will try to join that effort Saturday as we hope to finish with the university today.
Roberto Leon