On September 10, Irma made landfall in the Florida Keys as a category 4 hurricane. According to recent media reports, the storm caused more than 6.5 million people to evacuate, 134 fatalities and more than $50 billion in damages.

Two weeks later, College of Engineering and Computing Assistant Professor Inthuorn Sasanakul, civil engineering, joined teams from the Geotechnical Extreme Events Reconnaissance (GEER) Association, supported by the National Science Foundation, to study the effects of the hurricane.

It’s important to have South Carolina data to use for designs in South Carolina. We have many natural hazards in the state, including earthquakes. Local data collected and analyzed here to study the effects of these hazards can result in more cost-efficient designs relatively quickly.

- Inthuorn Sasanakul

GEER released a preliminary report describing work the teams completed in collaboration with federal, state, and local organizations in Florida. The work focused on collecting perishable data and observing the geotechnical impacts of storm surge, wave loading, and flooding that caused soil erosion, damage to infrastructure and exposed foundations.

“Irma was devastating to Florida; its effects will be felt for a long time,” Sasanakul says. “Fortunately, the data we collected will become a useful case study, which should inform future civil and structural design and risk assessment for civil engineers.”

Sasanakul has quite a bit of experience with floods and hurricanes. She collected data from several dam failures during historic flooding in SC from Hurricane Joaquin in 2015. Sasanakul also received awards from the U.S. Army Corp. of Engineers, including the “Commander’s Award of Public Service,” in appreciation for her work with the Evaluation Task Force in New Orleans, LA, after Hurricane Katrina.

In South Carolina, she is often called upon by state and local officials to inspect structures to help prevent failures and recommend repairs needed to lessen the impact of natural hazards. Hurricanes and other natural hazards enable Sasanakul to study damaged dams, roads and help determine where failures might occur in the future. SC is prone to floods and hurricanes – even earthquakes.

Not only is Sasanakul’s expertise sought after, but the college’s civil engineering lab has equipment that isn’t available anywhere else in SC. She and her students use the lab to, among other research, model internal erosion in dams and levees. Internal erosion is a mechanical process that occurs when soil particles within a dam or its foundation are carried downstream by water flow through the dam and foundation. Unlike surface erosion, which is readily detected by routine inspection and can be repaired in timely manner; internal erosion may go unnoticed for years.

The college currently has the only geotechnical centrifuge facility in SC, and one of only three in the southeast. The centrifuge can be used for a wide range of studies, including transportation infrastructure efficiency – highways, railroads and bridges; resiliency of infrastructure – dams, levees and pipelines; to natural and man-made hazards, sustainable infrastructure and alternative energy infrastructure, among other applications. Sasanakul is currently working on a project with $530,000 of funding from the South Carolina Department of Transportation to help improve the seismic design of transportation systems, such as bridge foundations, road embankments and retaining walls.

Sasanakul is also developing a plan to research the dynamic properties of earthquakes. The goal is to have an Earthquake Centrifuge Modeling Facility that will position USC to become one of the leaders in earthquake research in the U.S. To do this, the college will need an earthquake shaker system to be installed on the existing centrifuge to enable earthquake modeling tests. 

“It’s important to have South Carolina data to use for designs in South Carolina,” Sasanakul says. “We have many natural hazards in the state, including earthquakes. Local data collected and analyzed here to study the effects of these hazards can result in more cost-efficient designs relatively quickly.”

She’s also going to Puerto Rico at the end of October to investigate storm damage from Hurricane Maria, including dam failures and landslides, bridge foundations and scouring due to swift-flowing water, as well as coastal and river erosion.

Sasanakul’s work is never done, particularly after an historic hurricane season. Gathering important data now enables better preparation for future events.