Yousef Bozorgnia, professor of civil and environmental engineering, has developed earthquake ground motion models that are used worldwide for the seismic analysis and design of buildings, bridges, infrastructure and critical facilities. Prior to joining the UCLA faculty in July, Bozorgnia was a full professor-in-residence at UC Berkeley, where he remains an adjunct professor. He was also the executive director (2009-16) and the associate director (2004-09) of the Pacific Earthquake Engineering Research Center (PEER). At UCLA, Bozorgnia is part of the B. John Garrick Institute for the Risk Sciences. Bozorgnia answered questions on how he got interested in earthquake engineering, the importance of ground motion models and his teaching and research plans

When and why did you get interested in earthquake engineering?

In graduate school after taking courses in different disciplines I “fell in love” with earthquake engineering, and I am still very much passionate about it. Earthquake engineers can save lives and reduce financial loss caused by earthquakes by designing earthquake-resistant facilities.

I also very much enjoy multidisciplinary challenges of earthquake engineering. A major earthquake affects performances of facilities across disciplines. For example, buildings, bridges, power plants, electric networks, transportation systems, water and waste-water facilities, computer servers, cell phone towers, and many other facilities will be seriously affected. Financial losses from a major earthquake in California can easily exceed $200 billion. A competent earthquake engineer should have an area of expertise, but should be able to communicate well with experts in multiple disciplines.

What is a ground motion model and how does it help in regards to building and infrastructure design?

In order to design a new facility or evaluate seismic performance of an existing facility of any kind, we need to have an estimation of the level of ground shaking at the site in a future earthquake. Since we do not know where a future earthquake occurs and what its magnitude would be, the ground shaking estimate has to include uncertainty. In other words, it has to be probabilistic. A key component of such probabilistic estimate of ground shaking at a site is a  “Ground Motion Model” to provide scaling of the level of ground motion with various parameters such as earthquake magnitude, site-to-source distance, local soil conditions, and other factors.

An interesting part of the research in ground motion modeling is that the results of the research are almost immediately used in practice to design and evaluate all facilities. For example, in the United States, our community-based multidisciplinary research projects to ground motion modeling have immediate effects on almost anything that is attached to ground, from California to New York.

What are your research and teaching goals at UCLA?

The focus of my research at UCLA is to carry out multidisciplinary earthquake engineering projects with a goal of reducing the risk of earthquakes of becoming disasters. That is why I am affiliated with both the Civil and Environmental Engineering Department and the Garrick Institute for the Risk Sciences at UCLA. My teaching goal is to train students in civil engineering to have strong background in fundamentals of earthquake engineering, with a vision of applying their knowledge to reduce earthquake risks to a socio-economically acceptable level.