College of Engineering

We are going in and questioning, well, how safe is this dam? How big a risk does this situation pose?” Rice said.

Graduate students Nathan Braithwaite and Joe Zaleski both work with Rice on this project, and Rice will look to hire two undergraduate students as well as one additional graduate student to assist him in the future.

Lourdes Polanco, a Ph.D. student, is working on a similar project with Rice for her thesis. Together, they must come up with a probability of failure, based on the subsurface configuration of the soils and their properties. To test the erosion under a levee, samples of soil under the levee are taken, measuring the permeability. The type of soil present and its permeability are both big factors when plugged into Rice’s method, and are telling in whether breakage due to an erosion event is likely.

Before Rice’s new method, which he is currently testing, there was a simplified geometric method that was often not applicable due to complex subsurface geometrics, Rice said. The method uses finite element analyses, and with a Monte Carlo simulation that selects random variables pertaining to the state of the profile where the erosion may occur, a more accurate probability of failure is produced. This project was made possible by start-up funding, but Rice is currently looking for funding sources.

“It provides a more real assessment of levee reliability,” Rice said. “Therefore, it will allow government, the (U.S. Army) Corps of Engineers and the Bureau of Reclamation, to assess more accurately what the risk that is related to specific levee reaches. This way they can be more effective in spending the money on their projects.”

The National Science Foundation funded Rice and graduate student Mandie Swainston $127,000 to research the hydraulic gradient required to initiate erosion. They are collaborating with Penn State University, and their own Tong Qiu, develop a method for predicting. Qiu uses a numerical model to predict what will happen to different soil grains when water flows through them. Qui takes the information Rice and Swainston collect during lab analysis and uses that data to validate his numerical model. This way Qui can apply his model in a real way, and build devices that allow him and his students to replicate the experience the model predicts.

The Utah Dam Safety Program is looking to fund Rice’s research in mitigating with an additional $10,000 after funding him with $5,000 last year. The project involves looking at the current designs for mitigating high water pressures in dams and levees using slotted pipes and gravel filters. Rice will look at the grain size of the sand or gravel filter in comparison to the slot size of the pipe, and come up with a relationship to match the appropriate filter with the pipe slot size.