When earthquakes occur, buildings can shift or fall. Often times, the failure is because of soil liquefaction, a phenomenon that occurs when loose, water-saturated soils lose shear strength in response to the sudden shaking from an earthquake, causing the soil to behave like a liquid.

When liquefaction happens, the ability of the soil to support foundations for buildings and bridges is reduced. But now, a new grant awarded by the National Science Foundation to a Boise State University civil engineering researcher aims to minimize soil liquefaction.

Researchers have come up with a way to minimize liquefaction through a technique called Induced Partial Saturation, or IPS, where nonhazardous chemicals are injected into the ground. This creates gas bubbles to help reduce saturation and the chance of the soil liquefying. The technique has been demonstrated to work in the lab, but thanks to the new grant, the promising technique will now be tested in field for the first time.

“The outcome of this research is far reaching, because it can be implemented in urban areas with a lot of infrastructure in place, which can have a worldwide impact on human safety and protection of properties from liquefaction hazard of earthquakes,” said Arvin Farid, an assistant professor of civil engineering. “This is a very nondestructive method that will work in both places that have buildings and places that do not.”

To conduct the study, engineers will pump the nonhazardous chemical solution through a well-engineered controlled method into different types of soils and measure the ability of the generated gas to mitigate the potential liquefaction caused by earthquakes. The researchers plan to test the technique at an NSF Network for Earthquake Engineering Simulation (NEES) site and at the Bruneau Sand Dunes, as well as other sites. They hope to acquire fundamental knowledge on the feasibility of the implementation of the method and the behavior of soils with induced partial saturation to verify the effectiveness of IPS as a liquefaction mitigation method.

Engineering researchers at Northeastern University, the University of Texas at Austin, the State University of New York at Buffalo, are also collaborating on the project with the help from the University of California Santa Barbara and the U.S.G.S, as part of the NSF’s National Earthquake Hazards Reduction Program.

The project is expected to take about three years to complete.

Source: Boise State University