Research:
I consider myself to be a well-rounded geotechnical engineer with diverse research interests. My most important contributions have been in the areas of geotechnical earthquake engineering and to the development of geotechnical centrifuge facilities and associated technology.
Recent research areas:
1. One of my more exciting accomplishments was the formulation of a model that describes acceleration spikes in liquefying soil by a shock wave phenomena. We noticed very slow moving sharp spikes of acceleration by repeated viewing of animations of acceleration profiles. The paper by Kutter and Wilson (91) was the first time anyone has recognized that shock wave theory can apply to sand as it de-liquefies due to dilatancy. I think this paper has several fundamental implications and puts a new perspective on ground motion predictions in liquefying sand.
2. Soil-Pile-Structure Interaction. In collaboration with Ross Boulanger, Dan Wilson, and several students we have conducted some of the most careful and detailed model tests conducted in this area. We have also made some significant advances in developing numerical procedures and verifying them by comparison to the model tests.
3. Liquefaction and Lateral Spreading. We have conducted several model tests that have shed light on this problem. We are trying to identify the factors that affect the amount and mechanisms of lateral flow and lateral spreading. We have looked at the effect of accumulation of water at an impermeable interface, and at the extent of remediation necessary to improve performance during earthquakes
4. I have been involved in several projects to advance the state-of-the-art of centrifuge modeling. These topics range from instrumentation and data processing, data animation and visualization, and substitute pore fluids to improve model similarity, new centrifuges and shakers and tools for shear wave velocity measurement in the centrifuge.
5. I am presently collaborating with Geoff Martin at USC and Tara Hutchinson at UCI on the nonlinear behavior of shallow foundations and soil-foundation-structure systems to severe moment and rotation loading caused by earthquakes.
6. I have also continued to work in the areas of material properties and constitutive modeling of soil and in dynamic behavior of reinforced earth.
With my colleagues, we have averaged more than a half million dollars per year in support for this facility over the last half dozen years or so. Recently, NSF announced the $4.6 million award to UC Davis to establish a NEES Geotechnical Centrifuge Facility; I am the PI of this project, but much of the credit for the successful proposal goes to co-PI’s in Civil (especially Dan Wilson), Mechanical, Electrical and Computer Science Engineering. Recently I have received research funding from PEER, USGS, NSF and Caltrans.
Teaching:
I really enjoy teaching, and continue to work hard in this area. Along with Tom Young and Dan Wilson, I instituted a new course on Data Acquisition, Visualization and Control. With Ross Boulanger, I organized a two day short course on Geotechnical Earthquake Engineering for the PEER Undergraduate Scholars Program.
I work hard on my teaching and I expect the students to work hard in return.