INDICADORES DEL DESEMPEÑO SOCIAL

Sri Sritharan

Most of you know by now that Nigel began his professional career in 1967 at Central Laboratories in Gracefield, a small suburb of Wellington in New Zealand. My professional career also began in Gracefield, about 200 meters from Central Laboratories in the Department of Scientific and Industrial Research (DSIR), in 1989-22 years later. I took this position after receiving my MS degree at the University of Auckland under the mentorship of Richard Fenwick. Richard, an incredible and talented researcher, was Tom Paulay’s first PhD student. Richard assigned a nonseismic project to me, thinking that I would not have much interest in seismic research as my home country of Sri Lanka is not a country that experiences frequent earthquakes.

While at Auckland, I developed interest in seismic engineering and I further delved into it when I joined DSIR as an Engineering Seismologist. While I enjoyed this research, it quickly became clear

that I wasn’t appreciating terms such as plastic hinge length, ductility and concrete spalling as I never had a feel for what these terms meant in real structures. To overcome this challenge, I decided to find the best experimental university to pursue my PhD. David Dowrick, my colleague at the time, suggested that I write to Nigel to see if I could work with him to pursue my PhD. Though he noted that Nigel’s interest was more in masonry, which was true at that time, I followed David’s advice and asked Nigel if I could study with him. I did, however, question if this plan would materialize, so I applied to

a few other schools.

Now and then, I would get a fax from Nigel informing me about the application process. I finally received a communication from Nigel indicating that the University of California at San Diego (UCSD) would accept my application, despite some restrictions by the UC system to limit admissions to international students. Nigel wrote happily that I was the only international student allowed to join his department that year. To this date, I have no idea why Nigel gave me a life-changing opportunity to study under him, but I think that it must be the Gracefield connection!

I was accepted, with full financial support, by a few other universities, including Stanford University. Several of my friends and colleagues encouraged me to attend Stanford, as it’s a more prestigious university. I knew that Stanford was another excellent opportunity, that my seismology background would be well received at this institution. However, this opportunity was not in line with why I wanted to do a PhD at the first place. I informed Nigel of my dilemma and he didn’t hesitate to tell me that there was no better place to pursue my PhD than at UCSD! Thus, my decision was made.

As I was preparing to move to San Diego, a couple of unexpected events happened. First, my application for New Zealand citizenship came through and I was advised to go through a special ceremony so that I could go to San Diego as a “Kiwi”. I happily went through the ceremony, though doing so created some immigration-related challenges. Second, a few days before my departure a young beautiful girl walked into my office and introduced herself as Rebecca Priestley. Apparently, Rebecca was hired as a journalist at DSIR. I asked her if she had any connection to my new boss in San Diego… with a smile,

she blurted, “He is my dad …you like that concrete stuff? Condolences!” Later I found out Rebecca came to see me after she found out that I was leaving DSIR to join Nigel’s research group.

I left for San Diego a couple of weeks early as Nigel advised me to attend the Tom Paulay symposium. I previously met Tom during my MS study at Auckland. When he found out that I was working with Richard, he fondly suggested that I call him a “grandpa”, given that I was his student’s student. When I arrived in San Diego and met Nigel at the Tom Paulay symposium, his first concern was about my well-

being. Then with a smile, he reminded me that I made the right decision to come to UCSD. As the school quarter began, I started taking classes, including one taught by Nigel. The depth and breadth of topics that he covered in his classes were incredible. He was ready to tackle any questions that the students posed. There were plenty of them partly because the class had some experienced engineers from California- -including Jay Holombo and Robert Dowell. I recall Nigel enjoying the interactions he had with the students and often challenging them (on the spot) to make sure they learned and retained what he taught. One day in class, I asked a silly question without thinking it through. He turned, looked at me with a cunning smile, paused until I realized whatever I said was “nonsense” (one of Nigel’s favorite words), and finally turned back without saying a word and continued to teach class. No matter how blunt Nigel might have been, he readily appreciated when there was good feedback from his students. He took a great deal of pride in his students’ success, whether it was in doing well on exams, oral defenses or conference presentations.

Over the course of my PhD career, I took every class that Nigel offered; this included seismic design, bridge design, assessment and retrofit of structures, masonry, and prestressed concrete. The classes

were useful, informative, and challenging. I also started making frequent visits to the Powell lab where there was a seismic test almost every other day. If Nigel happened to be in the lab, he made sure the students understood what was being tested and what could be learned from the test observations. The combination of Nigel’s classes and the opportunity to witness tests in the lab tremendously enhanced my fundamental seismic knowledge. I knew then that I was at the right place with the right professor. Knowing what I know now, “clearly” (another Nigel’s favorite word) seismic design knowledge grew significantly through the 80s and 90s and Nigel/ UCSD played integral roles in creating that knowledge. I now realize that some of us were incredibly fortunate to be students in the middle of such tremendous seismic advancements at UCSD, as well as being closely associated with Nigel. This unique opportunity, along with what I gained from Nigel’s classes, formed the foundation of my seismic knowledge and provided me with the confidence to teach seismic-related courses.

Nigel recommended a few topics for my PhD research; then we narrowed it down to two: bridge joints and displacement-based design (DBD). Both were excellent choices, but the bridge joint project had a clearly defined experimental program. I chose to do research on a new design method for bridge joints. My first test went very well and I gained confidence in experimental research. Nigel left me in

charge of the second test and that didn’t go well. We applied the first load step, expecting a 2.5 mm (0.1 in.) of displacement at the column top and the next thing I knew, the column was leaning with a displacement of about 115 mm (4.5 in)! There was noticeable damage to the column and cracking on the joint, though we hadn’t even started the test. The technician acknowledged this and indicated that he knew what went wrong. I ran back to Nigel’s office, thinking that this would be the end my PhD research. When he saw me, he knew something went wrong in the lab and that I was really stressed. As I anxiously explained the mishap, he was very calm and attentive. He put his arm around my shoulder, and said things happen and that we could still get useful information from the test. He walked back with me to the lab, assessed the situation and made sure we had a plan to move forward. This is just one example of how gently he treated his students. Looking back, he was absolutely right that I was still able to extract valuable information from that test. Interestingly, I have witnessed mishaps in the tests conducted by my own students. A big “thank you” to Nigel for teaching me to remain calm and help my students get through their tests. What a wonderful mentor!

As I progressed through more tests in the lab at UCSD, I continued to gain confidence and was then ready to perform more complex tests. Instead of testing one joint at a time, I wanted to test multiple joints in a frame, knowing we could learn more from such tests. Nigel was at ease in providing such

freedom to his students as they matured and strongly encouraged them to be as independent as possible. I’m not sure if he ever realized this, but when he supported a research idea or test plan, it gave his

students a moral boost and the confidence that they were heading down the right path.

At the end of my first quarter in 1993, Nigel checked with me to see what my plan for the Christmas holiday was. I was new to California and had no plans. He invited me to his Idyllwild house where he spent his Christmas holidays with his family. He made sure there was a means for me to get there. I joined him and his family and friends for Christmas Eve dinner and stayed at his house. The next morning more people joined. Nigel and Jan’s (his wife) New Year’s Day tradition included a walk up into the mountains and lunch—we all had great time! This then became my tradition during Christmas breaks. Just like we learned about concrete, we learned about other aspects of life from Nigel—like

how to relax and enjoy life. I then realized Nigel wanted to make sure each of his students had a plan for the Christmas holidays. The domestic students went back to their families and he made sure the international students had some plans or that they were invited to join his family.

After I earned my PhD, I stayed at UCSD and continued to work with Nigel for about 18 months as a post-doc. My main responsibility was to build and test the PRESSS building. This consisted of precast

concrete and unbonded post-tensioning—the very first test structure designed to resist seismic loads using unbonded post-tensioning as the primary thesis. This building was also the largest and tallest to be tested inside a laboratory at that time!

My research efforts related to the PRESSS building precipitated another unique opportunity for my academic growth and continued close interactions with Nigel. After completing this research project, I accepted a position at Iowa State University. Nigel wanted to know how I felt about accepting the

position of assistant professor, since being a student and researcher is one thing, but being a teacher and building a research program of my own was a completely different challenge. I expressed my doubts and how I wasn’t sure if I could succeed. His response was—being over-confident is not good, but understand that a little bit of lack of confidence is good for you; “it helps you to be successful in

what you do,” he said with a smile. That statement has resonated with me to this day and has helped me during successful times and challenging times.

My purpose in sharing this tribute to Nigel is not just to impart what I think of Nigel and what my interactions with him were. I want you to get a sense of his personality and his life. If you have known Nigel and interacted with him, I’m sure you felt his presence just as I did. Nigel was “clearly” one-of-

a-kind—brilliant, elegant, quick, and witty—with no patience for (technical) “nonsense”.